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单选题 (三角函数基础068)如图,在Rt△ABC中,∠C=90°,sinA=
,AB=10,D是AC的中点,则BD的长度为( )
A. 5
B. 20-
C. 10-
D. 2
学科：高等数学
时间：2023-10-15 12:49:43
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题目1单选题
(三角函数基础076)已知2sinα﹣3tan30°=0,则锐角α为( )A. 45°B. 30°C. 15°D. 60°
题目2单选题
(三角函数基础057)如图,在菱形ABCD中,∠ABC=120°,对角线AC=4<img src="https://tihai-oss-cloud.itihey.com/img/b8794384c7480dd3ef0955f90a9b9bfd.png">,则菱形ABCD的周长为( )<img src="https://tihai-oss-cloud.itihey.com/img/9ea599bcded14c242919686c93542d8f.png">A. 20B. 12<img src="https://tihai-oss-cloud.itihey.com/img/b8794384c7480dd3ef0955f90a9b9bfd.png">C. 16D. 8<img src="https://tihai-oss-cloud.itihey.com/img/b8794384c7480dd3ef0955f90a9b9bfd.png">
题目3单选题
(三角函数基础001)tan45°的值为( )A. 2B. -1C. -2D. 1
题目4单选题
(三角函数基础071)如图,在△ABC中,AB=AC=10,点D是边BC上一动点(不与B、C重合),∠ADE=∠B=α,DE交AC于点E,且cosα=<img src="https://tihai-oss-cloud.itihey.com/img/b5b4c26fc923f2811714b0636d5a52a2.png">,则线段CE的最大值为( )<img src="https://tihai-oss-cloud.itihey.com/img/6f97810d515b05b17a93590f98922f8f.png">A. 8.1B. 7.5C. 6.4D. 9.2
题目5单选题
(三角函数基础068)如图,在Rt△ABC中,∠C=90°,sinA=<img src="https://tihai-oss-cloud.itihey.com/img/fe586745dbe4ad22caaa820fb7677948.png">,AB=10,D是AC的中点,则BD的长度为( )<img src="https://tihai-oss-cloud.itihey.com/img/5e5170b3ad0b0525d02e1010dc8208b5.png">A. 5<img src="https://tihai-oss-cloud.itihey.com/img/b8794384c7480dd3ef0955f90a9b9bfd.png">B. 20-<img src="https://tihai-oss-cloud.itihey.com/img/b8794384c7480dd3ef0955f90a9b9bfd.png">C. 10-<img src="https://tihai-oss-cloud.itihey.com/img/b8794384c7480dd3ef0955f90a9b9bfd.png">D. 2<img src="https://tihai-oss-cloud.itihey.com/img/c8076653438d0ed96b356a393b75dae7.png">
题目6单选题
(三角函数基础009)如图,AB是斜靠在墙上的长梯,AB与地面夹角为α,当梯顶A下滑1m到A′时,梯脚B滑到B′,A'B'与地面的夹角为β,若tanα=<img src="https://tihai-oss-cloud.itihey.com/img/779963ee1d4208bf525de459c2c9a807.png">,BB'=1m,则cosβ=( )<img src="https://tihai-oss-cloud.itihey.com/img/cf2f2505d7620a01cc951d9f7228252f.png">A. <img src="https://tihai-oss-cloud.itihey.com/img/b9febc74c112d3724a163c7b9b968758.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/ed09b1093c49da4bc23ee4f044273bad.png">C. <img src="https://tihai-oss-cloud.itihey.com/img/fe586745dbe4ad22caaa820fb7677948.png">D. <img src="https://tihai-oss-cloud.itihey.com/img/b5b4c26fc923f2811714b0636d5a52a2.png">
题目7单选题
(三角函数基础051)如图所示,某建筑物楼顶有信号塔EF,卓玛同学为了探究信号塔<img src="https://tihai-oss-cloud.itihey.com/img/0ea6ee47cd9ecc5d3fe58179e8f3622f.png">的高度,从建筑物一层A点沿直线AD出发,到达C点时刚好能看到信号塔的最高点F,测得仰角∠ACF=60°,AC长7米.接着卓玛再从C点出发,继续沿AD方向走了8米后到达B点,此时刚好能看到信号塔的最低点E,测得仰角∠B=30°.(不计卓玛同学的身高)则信号塔EF的高度为( ).<img src="https://tihai-oss-cloud.itihey.com/img/6013314ec9de17da3004652db0d4d424.png">A. 4mB. 4<img src="https://tihai-oss-cloud.itihey.com/img/b8794384c7480dd3ef0955f90a9b9bfd.png">mC. 2<img src="https://tihai-oss-cloud.itihey.com/img/b8794384c7480dd3ef0955f90a9b9bfd.png">mD. 2m
题目8单选题
(三角函数基础017)在△ABC中,<img src="https://tihai-oss-cloud.itihey.com/img/a08b02b952ba15ddda75962ad585b800.png">,BC=2,<img src="https://tihai-oss-cloud.itihey.com/img/016777480888c1233ad72ee222cadc44.png">,则边AC的长是( )A. <img src="https://tihai-oss-cloud.itihey.com/img/779963ee1d4208bf525de459c2c9a807.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/5d61445c0cadd03a5984e7c18c4db734.png">C. 3D. <img src="https://tihai-oss-cloud.itihey.com/img/361b664af38b27956545458648205f4b.png">
题目9单选题
(三角函数基础016)如图,小正方形的边长均为1, <img src="https://tihai-oss-cloud.itihey.com/img/c0494cb36ab1b5da4a3e872266dc18e2.png"> A、B、C分别是小正方形的三个顶点,则sin∠BAC的值为( )A. <img src="https://tihai-oss-cloud.itihey.com/img/bc3086157932f16504cbe340dff620ed.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/c3be6af53f947ffc2c3c858f479ce0ad.png">C. 1D. <img src="https://tihai-oss-cloud.itihey.com/img/054b12d1c34151467e3cab42acaf56af.png">
题目10单选题
(三角函数基础041)在△ABC中,AB=8,BC=6,∠B为锐角且<img src="https://tihai-oss-cloud.itihey.com/img/46ba9340873e36fed4c4e81bcdd271d1.png">,则△ABC的面积为( )<img src="https://tihai-oss-cloud.itihey.com/img/8f0c08bfa3788778c00e57c28ab510c1.png">A. 12<img src="https://tihai-oss-cloud.itihey.com/img/b8794384c7480dd3ef0955f90a9b9bfd.png">B. 2<img src="https://tihai-oss-cloud.itihey.com/img/b8794384c7480dd3ef0955f90a9b9bfd.png">C. 6<img src="https://tihai-oss-cloud.itihey.com/img/b8794384c7480dd3ef0955f90a9b9bfd.png">D. <img src="https://tihai-oss-cloud.itihey.com/img/b8794384c7480dd3ef0955f90a9b9bfd.png">
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