已知函数f(x)=2sin^2x+sin2x 若x∈[0,π/2],求使f(x)为正值的集合
问题描述:
已知函数f(x)=2sin^2x+sin2x 若x∈[0,π/2],求使f(x)为正值的集合
答
f(x)=1-cos2x+sin2x
=√2sin(x-π/4)+1>0
sin(x-π/4)>-√2/2
是x的集合?
-π/4