已知函数F(x)=根号3(sin^2X-cos^2X)+2sinXcosX.(1)X属于[0,2π/3]时,求F(x)的值域.(2)求F(x)的递增区间
问题描述:
已知函数F(x)=根号3(sin^2X-cos^2X)+2sinXcosX.(1)X属于[0,2π/3]时,求F(x)的值域.
(2)求F(x)的递增区间
答
buzhidao
答
F(x)=根号3(sin^2X-cos^2X)+2sinXcosX
=√3cos2x+sin2x
=2sin(2x+π/3)
(1) X属于[0,2π/3] 2x+π/3属于[π/3,5π/3]
2sin(2x+π/3)属于[-2,2]
值域为 [-2,2]
(2)
2kπ-π/2