作业帮a=sin(cos210°)和b=sin(sin210°),a,b哪个大
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a=sin(cos210°)和b=sin(sin210°),a,b哪个大
a=sin(cos210°)和b=sin(sin210°),a,b哪个大
a=sin(cos210°)和b=sin(sin210°),a,b哪个大
a=sin(cos210°)和b=sin(sin210°),a,b哪个大
210°在第三象限,
cos210°= 负值 = - cos30°= √3/2 ≈ - 0.866
sin210°= 负值 = - sin30°=1/2 = 0.5
而sinx是奇函数 sin(-x) = - sinx
a = sin(cos210°) = - sin (cos30°) = - sin(0.866)
b=sin(sin210°) = - sin(sin30) = - sin(0.5)
所以 b 大 注意 b 的绝对值大,但带上负号就小了
1就相当与57度左右，a=sin[-(根号3)/2]，b=sin(-1/2),因为在第四象限中正弦函数为增函数，所以b更大
a=sin(cos210°)和b=sin(sin210°),a,b哪个大
如题 a=sin(cos210°)和b=sin(sin210°),a,b哪个大请说明为什么
cos210°=?
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