设f(x)=根号1-x化简f(sin2)+f(sin(-2))1.设f(x)=根号1-x化简f(sin2)+f(sin(-2))2_数学解答

设f(x)=根号1-x化简f(sin2)+f(sin(-2))
1.设f(x)=根号1-x化简f(sin2)+f(sin(-2))
2.已知tanθ=2,求2sinθ的平方+3sin2θ+1
3.若sinθ:sinθ/2=8:5求cosθ

人气：254 ℃　时间：2020-01-24 20:27:51

解答

1、
f(sin2)+f(sin(-2))
=√(1-sin2)+√[1-sin(-2)]
=√(1-sin2)+√(1+sin2)
1-sin2=(sin1)^2+(cos1)^2-2sin1cos1
=(sin1-cos1)^2
同理1+sin2=(sin1+cos1)^2
因为π/4