> 数学 >
已知函数f(x)=2sin^2+2sinxcosx+1,求
(1)f(x)的最小正周期;
(2)f(x)的单调递增区间.
人气:291 ℃ 时间:2020-02-05 16:38:29
解答
(1)
f(x)=2sin^2x+2sinxcosx+1
=1-cos2x +sin2x +1
=√2(√2/2sin2x-√2/2cos2x)+2
=√2sin(2x-π/4)+2
f(x)的最小正周期 T=2π/2=π;
(2)
f(x)的单调递增区间即是sin(2x-π/4)的递增区间,
由-π/2+2kπ≤2x-π/4≤π/2+2kπ
-π/4+2kπ≤2x≤3π/4+2kπ
-π/8+kπ≤x≤3π/8+kπ
f(x)的单调递增区间为[-π/8+kπ,3π/8+kπ].
推荐
猜你喜欢
© 2024 79432.Com All Rights Reserved.
电脑版|手机版