26.2 锐角三角函数的计算 预学检验+课堂导学+同步练习（含答案）2023-2024学年冀教版数学九年级上册

第二十六章　解直角三角形 26. 2 锐角三角函数的计算 INCLUDEPICTURE"复习回顾.tif" INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\复习回顾.tif" \* MERGEFORMATINET INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\复习回顾.tif" \* MERGEFORMATINET 1．用计算器求－53，按键的顺序正确的是(　　) 2．用四舍五入法对0.060 45取近似值，错误的是(　　) A．0.1(精确到0.1) B．0.06(精确到百分位) C．0.061(精确到千分位) D．0.060 5(精确到0.000 1) 3．在下面的表中，填出 30°，45°，60°角的正弦值、余弦值和正切值． 30° 45° 60° sin α cos α tan α INCLUDEPICTURE"预习效果检测.tif" INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\预习效果检测.tif" \* MERGEFORMATINET INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\预习效果检测.tif" \* MERGEFORMATINET 1．用计算器计算sin 24°的值，以下按键顺序正确的是(　　) A. B. C. D. 2．如图，一座厂房屋顶人字架的跨度AC＝12 m，上弦AB＝BC，∠BAC＝25°.若用科学计算器求上弦AB的长，则下列按键顺序正确的是(　　) INCLUDEPICTURE"image3324.tif" INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\image3324.tif" \* MERGEFORMATINET INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\image3324.tif" \* MERGEFORMATINET A. 　 B. C. D. 3．用科学计算器计算：＋3tan 56°(结果精确到0.01)． INCLUDEPICTURE"课堂导学.tif" INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\课堂导学.tif" \* MERGEFORMATINET INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\课堂导学.tif" \* MERGEFORMATINET INCLUDEPICTURE"W21.tif" INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\W21.tif" \* MERGEFORMATINET INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\W21.tif" \* MERGEFORMATINET 知识点1 用计算器求三角函数值INCLUDEPICTURE"L1.tif" INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\L1.tif" \* MERGEFORMATINET INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\L1.tif" \* MERGEFORMATINET [2023威海一模利用科学计算器计算cos 35°，下列按键顺序正确的是(　　) A.INCLUDEPICTURE"image3336.tif" INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\image3336.tif" \* MERGEFORMATINET INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\image3336.tif" \* MERGEFORMATINET B.INCLUDEPICTURE"image3337.tif" INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\image3337.tif" \* MERGEFORMATINET INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\image3337.tif" \* MERGEFORMATINET C.INCLUDEPICTURE"image3338.tif" INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\image3338.tif" \* MERGEFORMATINET INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\image3338.tif" \* MERGEFORMATINET D.INCLUDEPICTURE"image3339.tif" INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\image3339.tif" \* MERGEFORMATINET INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\image3339.tif" \* MERGEFORMATINET 变式1用计算器求下列各式的值(结果精确到0.000 1)： (1)sin 47°；　　(2)sin 12°30′； (3)cos 25°18′；(4)sin 18°＋cos 55°－tan 59°. 　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 知识点2 已知三角函数值用计算器求角度 INCLUDEPICTURE"L2.tif" INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\L2.tif" \* MERGEFORMATINET INCLUDEPICTURE "D:\\课件\\九数JJ河北（北京）\\L2.tif" \* MERGEFORMATINET 已知sin A＝0.501 8，用计 ... ...