| | |
| | | <p><b>相关链接</b></p> |
| | | <p class="block">魔方是由6个不同颜色的面组成的正方体,它可组成约4 325亿亿种不同颜色的组合,其最佳复原魔方颜色组合的方法是用数学方法研究出来的.</p> |
| | | </div> |
| | | <div class="bk-hzjl"> |
| | | <div class="bj1-hzjl"> |
| | | <p class="left"> |
| | | <img class="img-gn2" alt="" src="../../assets/images/hzjl.jpg" /> |
| | | </p> |
| | | </div> |
| | | <examinations :cardList="questionData[78] ? questionData[78][1] : []" :hideCollect="true" sourceType="json" v-if="questionData"> |
| | | </examinations> |
| | | </div> |
| | | <p class="center"><img class="img-c" alt="" src="../../assets/images/0082-2.jpg" /></p> |
| | | <p class="img">图3-2</p> |
| | | <p><span class="zt-ls"><b>例3</b></span> 如图3-2所示,一个边长是<i>a</i>的正方体,体积是<i>V</i>,写出体积<i>V</i> 随边长<i>a</i> |
| | |
| | | <p>其中<i>a</i>是自变量,定义域为{<i>a</i>|<i>a</i>>0}.</p> |
| | | <p class="left"><img class="img-gn" alt="" src="../../assets/images/stlx.jpg" /></p> |
| | | <div class="bj"> |
| | | <examinations :cardList="questionData[78]" :hideCollect="true" sourceType="json" inputBc="#d3edfa" |
| | | <examinations :cardList="questionData[78] ? questionData[78][2] : []" :hideCollect="true" sourceType="json" inputBc="#d3edfa" |
| | | v-if="questionData" ></examinations> |
| | | </div> |
| | | </div> |
| | |
| | | <p>所以函数<i>f</i>(<i>x</i>)的定义域是{<i>x</i>|<i>x</i>≥-2且<i>x</i>≠3}.</p> |
| | | <p class="left"><img class="img-gn" alt="" src="../../assets/images/stlx.jpg" /></p> |
| | | <div class="bj" > |
| | | <examinations :cardList="questionData[80]" :hideCollect="true" sourceType="json" |
| | | <examinations :cardList="questionData[80]" :hideCollect="true" sourceType="json" inputBc="#d3edfa" |
| | | v-if="questionData" ></examinations> |
| | | </div> |
| | | </div> |
| | |
| | | <div class="page-box" page="81"> |
| | | <div v-if="showPageList.indexOf(81) > -1"> |
| | | <ul class="page-header-odd fl al-end"> |
| | | <li>074</li> |
| | | <li>074-076</li> |
| | | <li>数学.基础模块</li> |
| | | <li>上册</li> |
| | | </ul> |
| | | <div class="padding-116"> |
| | | <h3 id="c026">习题3.1<span class="fontsz2">>>></span></h3> |
| | | <div class="bj" > |
| | | <examinations :cardList="questionData[81]" :hideCollect="true" sourceType="json" |
| | | <examinations :cardList="questionData[81]" :hideCollect="true" sourceType="json" inputBc="#d3edfa" |
| | | v-if="questionData" ></examinations> |
| | | </div> |
| | | </div> |
| | | </div> |
| | | </div> |
| | | <!-- 075 --> |
| | | <div class="page-box" page="82"> |
| | | <div v-if="showPageList.indexOf(82) > -1"> |
| | | <ul class="page-header-box"> |
| | | <li> |
| | | <p>第三单元 函数</p> |
| | | </li> |
| | | <li> |
| | | <p><span>075</span></p> |
| | | </li> |
| | | </ul> |
| | | <div class="padding-116"> |
| | | <div class="bj"> |
| | | <p class="center"><img class="img-c" alt="" src="../../assets/images/0086-1.jpg" /></p> |
| | | <p class="img">第2(2) 题图</p> |
| | | <p>3.解答题.</p> |
| | | <p>(1) 小梁第一季度和第二季度每月手机费充值如表3-3所示,请用函数的概念描述小梁每月手机费充值金额<i>y</i>(元)与月份<i>x</i>的对应关系.</p> |
| | | <p class="img">表3-3</p> |
| | | <p class="center"><img class="img-a" alt="" src="../../assets/images/0086-2.jpg" /></p> |
| | | <p>(2) 求下列函数的定义域.</p> |
| | | <p>①<math display="0"> |
| | | <mi>f</mi> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">(</mo> |
| | | <mi>x</mi> |
| | | <mo data-mjx-texclass="CLOSE">)</mo> |
| | | </mrow> |
| | | <mo>=</mo> |
| | | <mfrac> |
| | | <mi>x</mi> |
| | | <mrow> |
| | | <mi>x</mi> |
| | | <mo>−</mo> |
| | | <mn>1</mn> |
| | | </mrow> |
| | | </mfrac> |
| | | </math>;</p> |
| | | <p>②<math display="0"> |
| | | <mi>f</mi> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">(</mo> |
| | | <mi>x</mi> |
| | | <mo data-mjx-texclass="CLOSE">)</mo> |
| | | </mrow> |
| | | <mo>=</mo> |
| | | <msqrt> |
| | | <mi>x</mi> |
| | | <mo>+</mo> |
| | | <mn>3</mn> |
| | | </msqrt> |
| | | <mo>+</mo> |
| | | <msqrt> |
| | | <mn>2</mn> |
| | | <mo>−</mo> |
| | | <mi>x</mi> |
| | | </msqrt> |
| | | </math>;</p> |
| | | <p>③<math display="0"> |
| | | <mi>f</mi> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">(</mo> |
| | | <mi>x</mi> |
| | | <mo data-mjx-texclass="CLOSE">)</mo> |
| | | </mrow> |
| | | <mo>=</mo> |
| | | <msqrt> |
| | | <msup> |
| | | <mi>x</mi> |
| | | <mrow> |
| | | <mn>2</mn> |
| | | </mrow> |
| | | </msup> |
| | | <mo>−</mo> |
| | | <mn>5</mn> |
| | | <mi>x</mi> |
| | | <mo>+</mo> |
| | | <mn>6</mn> |
| | | </msqrt> |
| | | </math>.</p> |
| | | <p><span class="bj-sp"><b>水平二</b></span></p> |
| | | <p>1.填空题.</p> |
| | | <p>(1) 若函数<i>f</i>(<i>x</i>)=2<i>x</i>+<i>b</i>,且<i>f</i>(-1)=5,则<i>b</i>=____;</p> |
| | | <p>(2) 若函数<math display="0"> |
| | | <mi>f</mi> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">(</mo> |
| | | <mi>x</mi> |
| | | <mo data-mjx-texclass="CLOSE">)</mo> |
| | | </mrow> |
| | | <mo>=</mo> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">{</mo> |
| | | <mtable columnspacing="1em" rowspacing="4pt"> |
| | | <mtr> |
| | | <mtd> |
| | | <mn>2</mn> |
| | | <mo>−</mo> |
| | | <mi>x</mi> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo>≤</mo> |
| | | <mn>0</mn> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | <mtr> |
| | | <mtd> |
| | | <msup> |
| | | <mi>x</mi> |
| | | <mrow> |
| | | <mn>2</mn> |
| | | </mrow> |
| | | </msup> |
| | | <mo>−</mo> |
| | | <mn>3</mn> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo>></mo> |
| | | <mn>0</mn> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | </mtable> |
| | | <mo data-mjx-texclass="CLOSE" fence="true" stretchy="true" symmetric="true"></mo> |
| | | </mrow> |
| | | </math>,则<i>f</i>(-1)=____,<i>f</i>(<i>f</i>(-1))=</p> |
| | | <p>____;</p> |
| | | <p>(3) 若函数<i>f</i>(<i>t</i>-1)=4<i>t</i>+7,则<i>f</i>(2)=____.</p> |
| | | <p>2.求下列函数的定义域.</p> |
| | | <p>(1) <math display="0"> |
| | | <mi>f</mi> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">(</mo> |
| | | <mi>x</mi> |
| | | <mo data-mjx-texclass="CLOSE">)</mo> |
| | | </mrow> |
| | | <mo>=</mo> |
| | | <msqrt> |
| | | <msup> |
| | | <mi>x</mi> |
| | | <mrow> |
| | | <mn>2</mn> |
| | | </mrow> |
| | | </msup> |
| | | <mo>−</mo> |
| | | <mn>16</mn> |
| | | </msqrt> |
| | | </math>;</p> |
| | | <p>(2) <math display="0"> |
| | | <mi>f</mi> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">(</mo> |
| | | <mi>x</mi> |
| | | <mo data-mjx-texclass="CLOSE">)</mo> |
| | | </mrow> |
| | | <mo>=</mo> |
| | | <mfrac> |
| | | <mn>1</mn> |
| | | <msqrt> |
| | | <msup> |
| | | <mi>x</mi> |
| | | <mrow> |
| | | <mn>2</mn> |
| | | </mrow> |
| | | </msup> |
| | | <mo>−</mo> |
| | | <mn>3</mn> |
| | | <mi>x</mi> |
| | | </msqrt> |
| | | </mfrac> |
| | | </math>;</p> |
| | | <p>(3) <math display="0"> |
| | | <mi>f</mi> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">(</mo> |
| | | <mi>x</mi> |
| | | <mo data-mjx-texclass="CLOSE">)</mo> |
| | | </mrow> |
| | | <mo>=</mo> |
| | | <msqrt> |
| | | <mn>5</mn> |
| | | <mo>−</mo> |
| | | <mrow> |
| | | <mo stretchy="false">|</mo> |
| | | </mrow> |
| | | <mn>3</mn> |
| | | <mi>x</mi> |
| | | <mo>−</mo> |
| | | <mn>1</mn> |
| | | <mo stretchy="false">|</mo> |
| | | </msqrt> |
| | | <mo>+</mo> |
| | | <mfrac> |
| | | <mn>1</mn> |
| | | <mrow> |
| | | <mi>x</mi> |
| | | <mo>−</mo> |
| | | <mn>2</mn> |
| | | </mrow> |
| | | </mfrac> |
| | | </math>.</p> |
| | | </div> |
| | | </div> |
| | | </div> |
| | | </div> |
| | | <!-- 076 --> |
| | | <div class="page-box" page="83"> |
| | | <div v-if="showPageList.indexOf(83) > -1"> |
| | | <ul class="page-header-odd fl al-end"> |
| | | <li>076</li> |
| | | <li>数学.基础模块</li> |
| | | <li>上册</li> |
| | | </ul> |
| | | |
| | | <div class="padding-116"> |
| | | <div class="bj"> |
| | | <p>3.已知函数<math display="0"> |
| | | <mi>f</mi> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">(</mo> |
| | | <mi>x</mi> |
| | | <mo data-mjx-texclass="CLOSE">)</mo> |
| | | </mrow> |
| | | <mo>=</mo> |
| | | <msqrt> |
| | | <msup> |
| | | <mi>x</mi> |
| | | <mrow> |
| | | <mn>2</mn> |
| | | </mrow> |
| | | </msup> |
| | | <mo>−</mo> |
| | | <mn>4</mn> |
| | | <mi>x</mi> |
| | | <mo>+</mo> |
| | | <mn>3</mn> |
| | | </msqrt> |
| | | </math>.</p> |
| | | <p>(1) 求函数的定义域;</p> |
| | | <p>(2) 比较<i>f</i>(5)与<i>f</i>(3)的大小;</p> |
| | | <p>(3) 求函数的值域.</p> |
| | | </div> |
| | | <h2 id="b016">3.2 函数的表示方法<span class="fontsz1">>>>>>>>></span></h2> |
| | | <h3 id="c027">3.2.1 函数的表示方法<span class="fontsz2">>>></span></h3> |
| | |
| | | <p>表3-4清晰地反映了年份与当年快递业务量(亿件)之间的对应关系.在实际生活中,用列表法表示变量之间对应关系的例子还有很多.例如,记录某人每天的消费情况、单位职工的每月薪资收入、银行使用的存款“利息表”等.</p> |
| | | </div> |
| | | </div> |
| | | </div> |
| | | <!-- 075 --> |
| | | <div class="page-box hidePage" page="82"> |
| | | </div> |
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| | | <div class="page-box hidePage" page="83"> |
| | | </div> |
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| | | <div class="page-box" page="84"> |
| | |
| | | <div class="bj1-hzjl"> |
| | | <p class="left"><img class="img-gn2" alt="" src="../../assets/images/hzjl.jpg" /></p> |
| | | </div> |
| | | <p class="block">分组探讨,例2中的函数能否用解析法表示?例3中的函数能否用列表法和解析法表示?比较函数的三种表示方法,它们各自的特点是什么?</p> |
| | | <examinations :cardList="questionData[85] ? questionData[85][1] : []" :hideCollect="true" sourceType="json" inputBc="#d3edfa" |
| | | v-if="questionData" ></examinations> |
| | | </div> |
| | | <p class="left"><img class="img-gn" alt="" src="../../assets/images/stlx.jpg" /></p> |
| | | <div class="bj"> |
| | | <examinations :cardList="questionData[85]" :hideCollect="true" sourceType="json" |
| | | <examinations :cardList="questionData[85] ? questionData[85][2] : []" :hideCollect="true" sourceType="json" inputBc="#d3edfa" |
| | | v-if="questionData" ></examinations> |
| | | </div> |
| | | </div> |
| | |
| | | <div class="bj1-hzjl"> |
| | | <p class="left"><img class="img-gn2" alt="" src="../../assets/images/hzjl.jpg" /></p> |
| | | </div> |
| | | <p class="block">依法纳税是每个公民的义务.查找国家征收个人所得税税率表, 并讨论:如果一个公司内两位员工一年的个人综合所得额分别为12万和15万,那么这两位员工所缴纳的个人所得税税额分别是多少? |
| | | </p> |
| | | <examinations :cardList="questionData[88] ? questionData[88][1] : []" :hideCollect="true" sourceType="json" |
| | | v-if="questionData" ></examinations> |
| | | </div> |
| | | <p class="left"><img class="img-gn" alt="" src="../../assets/images/stlx.jpg" /></p> |
| | | <div class="bj"> |
| | | <p>1.填空题.</p> |
| | | <p>(1) 若函数<math display="0"> |
| | | <mi>y</mi> |
| | | <mo>=</mo> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">{</mo> |
| | | <mtable columnspacing="1em" rowspacing="4pt"> |
| | | <mtr> |
| | | <mtd> |
| | | <mi>x</mi> |
| | | <mo>+</mo> |
| | | <mn>1</mn> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo>∈</mo> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">{</mo> |
| | | <mn>0</mn> |
| | | <mo>,</mo> |
| | | <mn>1</mn> |
| | | <mo>,</mo> |
| | | <mn>2</mn> |
| | | <mo data-mjx-texclass="CLOSE">}</mo> |
| | | </mrow> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | <mtr> |
| | | <mtd> |
| | | <mn>2</mn> |
| | | <mi>x</mi> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo>∈</mo> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">{</mo> |
| | | <mn>3</mn> |
| | | <mo>,</mo> |
| | | <mn>4</mn> |
| | | <mo data-mjx-texclass="CLOSE">}</mo> |
| | | </mrow> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | </mtable> |
| | | <mo data-mjx-texclass="CLOSE" fence="true" stretchy="true" symmetric="true"></mo> |
| | | </mrow> |
| | | </math>,则<i>f</i>(0)=____,<i>f</i>(3)=____;</p> |
| | | <p>(2) 若函数<math display="0"> |
| | | <mi>f</mi> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">(</mo> |
| | | <mi>x</mi> |
| | | <mo data-mjx-texclass="CLOSE">)</mo> |
| | | </mrow> |
| | | <mo>=</mo> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">{</mo> |
| | | <mtable columnspacing="1em" rowspacing="4pt"> |
| | | <mtr> |
| | | <mtd> |
| | | <mn>3</mn> |
| | | <mi>x</mi> |
| | | <mo>−</mo> |
| | | <mn>1</mn> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo><</mo> |
| | | <mn>0</mn> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | <mtr> |
| | | <mtd> |
| | | <msqrt> |
| | | <mi>x</mi> |
| | | </msqrt> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo>≥</mo> |
| | | <mn>0</mn> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | </mtable> |
| | | <mo data-mjx-texclass="CLOSE" fence="true" stretchy="true" symmetric="true"></mo> |
| | | </mrow> |
| | | </math>____,</p> |
| | | <p><i>f</i>(4)=____;</p> |
| | | <p>(3) 若函数<math display="0"> |
| | | <mi>f</mi> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">(</mo> |
| | | <mi>x</mi> |
| | | <mo data-mjx-texclass="CLOSE">)</mo> |
| | | </mrow> |
| | | <mo>=</mo> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">{</mo> |
| | | <mtable columnspacing="1em" rowspacing="4pt"> |
| | | <mtr> |
| | | <mtd> |
| | | <mn>3</mn> |
| | | <mi>x</mi> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo>≤</mo> |
| | | <mo>−</mo> |
| | | <mn>2</mn> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | <mtr> |
| | | <mtd> |
| | | <mn>2020</mn> |
| | | <mo>,</mo> |
| | | <mo>−</mo> |
| | | <mn>2</mn> |
| | | <mo><</mo> |
| | | <mi>x</mi> |
| | | <mo>≤</mo> |
| | | <mn>2</mn> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | <mtr> |
| | | <mtd> |
| | | <msup> |
| | | <mi>x</mi> |
| | | <mrow> |
| | | <mn>2</mn> |
| | | </mrow> |
| | | </msup> |
| | | <mo>−</mo> |
| | | <mn>1</mn> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo>></mo> |
| | | <mn>2</mn> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | </mtable> |
| | | <mo data-mjx-texclass="CLOSE" fence="true" stretchy="true" symmetric="true"></mo> |
| | | </mrow> |
| | | </math>,则<i>f</i>(-1)=____,<i>f</i>(0)=____,<i>f</i>(3)=____;</p> |
| | | <p>(4) 若函数<math display="0"> |
| | | <mi>f</mi> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">(</mo> |
| | | <mi>x</mi> |
| | | <mo data-mjx-texclass="CLOSE">)</mo> |
| | | </mrow> |
| | | <mo>=</mo> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">{</mo> |
| | | <mtable columnspacing="1em" rowspacing="4pt"> |
| | | <mtr> |
| | | <mtd> |
| | | <msup> |
| | | <mi>x</mi> |
| | | <mrow> |
| | | <mn>2</mn> |
| | | </mrow> |
| | | </msup> |
| | | <mo>+</mo> |
| | | <mn>3</mn> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo><</mo> |
| | | <mn>0</mn> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | <mtr> |
| | | <mtd> |
| | | <msqrt> |
| | | <mn>2</mn> |
| | | <mi>x</mi> |
| | | <mo>+</mo> |
| | | <mn>1</mn> |
| | | </msqrt> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo>≥</mo> |
| | | <mn>0</mn> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | </mtable> |
| | | <mo data-mjx-texclass="CLOSE" fence="true" stretchy="true" symmetric="true"></mo> |
| | | </mrow> |
| | | </math>____.</p> |
| | | <p>2.为了促销某品牌的薯片,某电商平台拟采取如下促销方式:每袋薯片原来的价格是6元,若顾客购买30袋及以上,则每袋的价格为5元.假设某顾客一次性购买这种薯片<i>x</i>袋,电商平台收款是<i>y</i>元. |
| | | </p> |
| | | <p>(1) 当<i>x</i><30,<i>x</i>∈<b>N</b>时,写出<i>y</i>与<i>x</i>的函数关系式;</p> |
| | | <examinations :cardList="questionData[88] ? questionData[88][2] : []" :hideCollect="true" sourceType="json" inputBc="#d3edfa" |
| | | v-if="questionData" ></examinations> |
| | | </div> |
| | | </div> |
| | | </div> |
| | |
| | | <div class="page-box" page="89"> |
| | | <div v-if="showPageList.indexOf(89) > -1"> |
| | | <ul class="page-header-odd fl al-end"> |
| | | <li>082</li> |
| | | <li>082-084</li> |
| | | <li>数学.基础模块</li> |
| | | <li>上册</li> |
| | | </ul> |
| | | |
| | | <div class="padding-116"> |
| | | <div class="bj"> |
| | | <p>(2) 用解析法表示函数<i>y</i>=<i>f</i>(<i>x</i>).</p> |
| | | <p>3.某市居民家庭燃气收费采用分段计费方式,如表3-8所示.</p> |
| | | <p>(1) 小黄家8月使用燃气46 m<sup>3</sup>,他家应付燃气费多少元;</p> |
| | | <p>(2) 用解析法表示每户居民家庭每月缴纳燃气费<i>y</i>(元)与使用燃气量<i>x</i>(<i>m</i><sup>3</sup>)的函数关系,并画出函数的图像.</p> |
| | | <p class="img">表3-8 某市居民家庭每月用燃气计费价格表</p> |
| | | <p class="center"><img class="img-a" alt="" src="../../assets/images/0093-1.jpg" /></p> |
| | | </div> |
| | | <h3 id="c029">习题3.2<span class="fontsz2">>>></span></h3> |
| | | <div class="bj"> |
| | | <p><span class="bj-sp"><b>水平一</b></span></p> |
| | | <p>1.选择题.</p> |
| | | <p>(1) 某商场有某品牌的电动车30辆可供出售,每辆售价2 000元,那么该商场出售电动车的营业额<i>y</i>(元)与出售的数量<i>x</i>之间的函数关系用解析法表示正确的是( ).</p> |
| | | <p>A.<i>y</i>=2 000<i>x</i></p> |
| | | <p>B.<i>y</i>=2 000<i>x</i>,<i>x</i>≤30</p> |
| | | <p>C.<i>y</i>=2 000<i>x</i>,<i>x</i>≤30,且<i>x</i>∈<b>N</b></p> |
| | | <p>D.<i>y</i>=30<i>x</i></p> |
| | | <p>(2) 若函数<math display="0"> |
| | | <mi>f</mi> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">(</mo> |
| | | <mi>x</mi> |
| | | <mo data-mjx-texclass="CLOSE">)</mo> |
| | | </mrow> |
| | | <mo>=</mo> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">{</mo> |
| | | <mtable columnspacing="1em" rowspacing="4pt"> |
| | | <mtr> |
| | | <mtd> |
| | | <msup> |
| | | <mi>x</mi> |
| | | <mrow> |
| | | <mn>2</mn> |
| | | </mrow> |
| | | </msup> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo>≤</mo> |
| | | <mn>0</mn> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | <mtr> |
| | | <mtd> |
| | | <mn>2</mn> |
| | | <mi>x</mi> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo>></mo> |
| | | <mn>0</mn> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | </mtable> |
| | | <mo data-mjx-texclass="CLOSE" fence="true" stretchy="true" symmetric="true"></mo> |
| | | </mrow> |
| | | </math>,则<i>f</i>(-1)+<i>f</i>(1)=( ).</p> |
| | | <p>A.0</p> |
| | | <p>B.2</p> |
| | | <p>C.3</p> |
| | | <p>D.4</p> |
| | | <p>2.市场上新上市的苹果价格是7.2元/kg,用解析法表示购买苹果应付款<i>y</i>(元)与购买质量<i>x</i>(kg )的函数关系.</p> |
| | | <p>3.某快递公司在<i>A</i>城内的运费价格如表3-9所示,用<i>x</i>(kg )表示物品的质量,<i>y</i>(元)表示快递物品的运费.</p> |
| | | </div> |
| | | </div> |
| | | </div> |
| | | </div> |
| | | <!-- 083 --> |
| | | <div class="page-box" page="90"> |
| | | <div v-if="showPageList.indexOf(90) > -1"> |
| | | <ul class="page-header-box"> |
| | | <li> |
| | | <p>第三单元 函数</p> |
| | | </li> |
| | | <li> |
| | | <p><span>083</span></p> |
| | | </li> |
| | | </ul> |
| | | <div class="padding-116"> |
| | | <div class="bj"> |
| | | <p class="img">表3-9</p> |
| | | <p class="center"><img class="img-a" alt="" src="../../assets/images/0094-1.jpg" /></p> |
| | | <p>(1) 某顾客在<i>A</i>城内快递物品,如果质量是2.5 kg,那么他应付快递费多少元?</p> |
| | | <p>(2) 用解析法表示函数<i>y</i>=<i>f</i>(<i>x</i>).</p> |
| | | <p>(3) 画出函数<i>y</i>=<i>f</i>(<i>x</i>)的图像.</p> |
| | | <p>4.某城市公交车2号线路共设置10站,乘车收费标准为:乘客若乘坐不超过6站则收费2元;若乘坐超过6 站则收费4元.用<i>x</i>表示乘车的站数,<i>y</i>表示收费金额.</p> |
| | | <p>(1) 用列表法表示公交车收费<i>y</i>与乘车的站数<i>x</i>之间的函数关系;</p> |
| | | <p>(2) 用解析法表示函数<i>y</i>=<i>f</i>(<i>x</i>);</p> |
| | | <p>(3) 画出函数<i>y</i>=<i>f</i>(<i>x</i>)的图像.</p> |
| | | <p>5.某商户以每千克30元的价格购入100 kg |
| | | 某种野生菌,并把野生菌放入冷库中,但最多只能存放15天.据预测,这批野生菌的单价每天将上涨0.2元.在不考虑其他因素的情况下,这批野生菌的售价<i>y</i>(元)是存放天数<i>x</i>的函数.</p> |
| | | <p>(1) 写出函数的定义域;</p> |
| | | <p>(2) 用解析法表示<i>y</i>与<i>x</i>的函数关系;</p> |
| | | <p>(3) 设一次性出售这批野生菌可获利<i>P</i>元,用解析法表示<i>P</i>与<i>x</i>的函数关系.</p> |
| | | <p><span class="bj-sp"><b>水平二</b></span></p> |
| | | <p>1.已知函数<math display="0"> |
| | | <mi>f</mi> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">(</mo> |
| | | <mi>x</mi> |
| | | <mo data-mjx-texclass="CLOSE">)</mo> |
| | | </mrow> |
| | | <mo>=</mo> |
| | | <mrow data-mjx-texclass="INNER"> |
| | | <mo data-mjx-texclass="OPEN">{</mo> |
| | | <mtable columnspacing="1em" rowspacing="4pt"> |
| | | <mtr> |
| | | <mtd> |
| | | <mi>x</mi> |
| | | <mo>+</mo> |
| | | <mn>2</mn> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo>≤</mo> |
| | | <mo>−</mo> |
| | | <mn>1</mn> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | <mtr> |
| | | <mtd> |
| | | <msup> |
| | | <mi>x</mi> |
| | | <mrow> |
| | | <mn>2</mn> |
| | | </mrow> |
| | | </msup> |
| | | <mo>,</mo> |
| | | <mo>−</mo> |
| | | <mn>1</mn> |
| | | <mo><</mo> |
| | | <mi>x</mi> |
| | | <mo><</mo> |
| | | <mn>2</mn> |
| | | <mo>,</mo> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | <mtr> |
| | | <mtd> |
| | | <mn>3</mn> |
| | | <mi>x</mi> |
| | | <mo>,</mo> |
| | | <mi>x</mi> |
| | | <mo>≥</mo> |
| | | <mn>2.</mn> |
| | | </mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | <mtd></mtd> |
| | | </mtr> |
| | | </mtable> |
| | | <mo data-mjx-texclass="CLOSE" fence="true" stretchy="true" symmetric="true"></mo> |
| | | </mrow> |
| | | </math>.</p> |
| | | <p>(1) 求<i>f</i>(0)+<i>f</i>(4)的值;</p> |
| | | <p>(2) 若<i>f</i>(<i>x</i>)=3,求<i>x</i>的值.</p> |
| | | <p>2.某市出租车的计价标准:按出租车实际行驶路程计费,4 km及以下收费10元,超过4 km的部分按2元/km计费.</p> |
| | | </div> |
| | | </div> |
| | | </div> |
| | | </div> |
| | | <!-- 084 --> |
| | | <div class="page-box" page="91"> |
| | | <div v-if="showPageList.indexOf(91) > -1"> |
| | | <ul class="page-header-odd fl al-end"> |
| | | <li>084</li> |
| | | <li>数学.基础模块</li> |
| | | <li>上册</li> |
| | | </ul> |
| | | <div class="padding-116"> |
| | | <div class="bj"> |
| | | <p>(1) 如果某人搭乘出租车行驶了20 km,那么他需要付费多少元?</p> |
| | | <p>(2) 请表示出租车收费<i>y</i>(元)与行驶的路程<i>x</i>(km) 之间的函数关系;</p> |
| | | <p>(3) 画出(2) 中函数的图像.</p> |
| | | <p>3.为鼓励居民节约用水,某自来水公司按表3-10的收费标准收取每户居民家庭每月水费.</p> |
| | | <p class="img">表3-10</p> |
| | | <p class="center"><img class="img-a" alt="" src="../../assets/images/0095-1.jpg" /></p> |
| | | <p>(1) 小明家8月的用水量是13 <i>t</i>,小王家8月的用水量是16 <i>t</i>,小明家和小王家分别应付水费多少元?</p> |
| | | <p>(2) 写出每户家庭居民每月付水费<i>y</i>(元)与用水量<i>x</i>(<i>t</i>)的函数关系,并画出该函数的图像;</p> |
| | | <p>(3) 若小李家9月付水费66元,则他家这个月的用水量是多少?</p> |
| | | <examinations :cardList="questionData[89]" :hideCollect="true" sourceType="json" inputBc="#d3edfa" |
| | | v-if="questionData" ></examinations> |
| | | </div> |
| | | <h2 id="b017">3.3 函数的单调性和奇偶性<span class="fontsz1">>>>>>>>></span></h2> |
| | | <h3 id="c030">3.3.1 函数的单调性<span class="fontsz2">>>></span></h3> |
| | |
| | | </p> |
| | | </div> |
| | | </div> |
| | | </div> |
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| | | <div class="page-box" page="92"> |
| | |
| | | <i>f</i>(-<i>x</i>)=(-<i>x</i>)+|-<i>x</i>|=-<i>x</i>+|<i>x</i>|=-(<i>x</i>-|<i>x</i>|)≠-<i>f</i>(<i>x</i>). |
| | | </p> |
| | | <p>所以,函数<i>f</i>(<i>x</i>)=<i>x</i>+|<i>x</i>|不是奇函数.</p> |
| | | <div class="bk-hzjl"> |
| | | <div class="bj1-hzjl"> |
| | | <p class="left"> |
| | | <img class="img-gn2" alt="" src="../../assets/images/hzjl.jpg" /> |
| | | </p> |
| | | </div> |
| | | <examinations :cardList="questionData[103] ? questionData[103][1] : []" :hideCollect="true" sourceType="json" v-if="questionData"> |
| | | </examinations> |
| | | </div> |
| | | <p>如果一个函数是奇函数或偶函数,那么就称这个函数具有<b>奇偶性</b>.否则,函数不具有奇偶性.</p> |
| | | <p><span class="zt-ls"><b>例7</b></span> 判断下列函数的奇偶性.</p> |
| | | <p>(1) <i>f</i>(<i>x</i>)=<i>x</i><sup>4</sup>;(2) <math display="0"> |
| | |
| | | <div class="bj1-hzjl"> |
| | | <p class="left"><img class="img-gn2" alt="" src="../../assets/images/hzjl.jpg" /></p> |
| | | </div> |
| | | <examinations :cardList="questionData[103]" :hideCollect="true" sourceType="json" |
| | | <examinations :cardList="questionData[103] ? questionData[103][2] : []" :hideCollect="true" sourceType="json" |
| | | v-if="questionData" ></examinations> |
| | | </div> |
| | | </div> |
| | |
| | | <div class="page-box" page="109"> |
| | | <div v-if="showPageList.indexOf(109) > -1"> |
| | | <ul class="page-header-odd fl al-end"> |
| | | <li>102</li> |
| | | <li>102-103</li> |
| | | <li>数学.基础模块</li> |
| | | <li>上册</li> |
| | | </ul> |
| | |
| | | <p class="center"><i>w</i>=-20(<i>x</i>-45)<sup>2</sup>+4 500.</p> |
| | | <p>所以,当<i>x</i>=45时,<i>w</i>的值最大,最大值是4 500.</p> |
| | | <p>答:当销售单价为45元时,该批发商每月可获得最大利润,最大利润是4 500元.</p> |
| | | </div> |
| | | </div> |
| | | </div> |
| | | <!-- 103 --> |
| | | <div class="page-box" page="110"> |
| | | <div v-if="showPageList.indexOf(110) > -1"> |
| | | <ul class="page-header-box"> |
| | | <li> |
| | | <p>第三单元 函数</p> |
| | | </li> |
| | | <li> |
| | | <p><span>103</span></p> |
| | | </li> |
| | | </ul> |
| | | <div class="padding-116"> |
| | | <p class="left"><img class="img-gn" alt="" src="../../assets/images/stlx.jpg" /></p> |
| | | <div class="bj"> |
| | | <examinations :cardList="questionData[110]" :hideCollect="true" sourceType="json" |
| | |
| | | </div> |
| | | </div> |
| | | </div> |
| | | </div> |
| | | <!-- 103 --> |
| | | <div class="page-box hidePage" page="110"> |
| | | </div> |
| | | <!-- 104 --> |
| | | <div class="page-box" page="111"> |
| | |
| | | }, |
| | | showNext(num) { |
| | | const number = this.thinkOne.findIndex((item, index) => index == num); |
| | | console.log(number); |
| | | this.thinkOne[number].isShow = true; |
| | | if (this.thinkIndex <= 2) { |
| | | this.thinkIndex++; |