已知函数f(x)=2cosxsin(x+π/3)-根号3sin^2x+sinxcosx 当x∈[0,π/4]时,f(x)

已知函数f(x)=2cosxsin(x+π/3)-根号3sin^2x+sinxcosx 当x∈[0,π/4]时,f(x)的值域
gg25 1年前 已收到1个回答 举报

xwxhl 春芽

共回答了19个问题采纳率:84.2% 举报

f(x)=2cosxsin(x+π/3)-√3*(sinx)^2+sinxcosx
=2cosx[sinxcos(π/3)+cosxsin(π/3)]-√3*(sinx)^2+sinxcosx
=sinxcosx+√3*(cosx)^2-√3*(sinx)^2+sinxcosx
=2sinxcosx+√3*[(cosx)^2-(sinx)^2]
=sin2x+√3*cos2x
=2sin(2x+π/3)
x∈[0,π/4]
2x∈[0,π/2]
2x+π/3∈[π/3,5π/6]
sin(2x+π/3)∈[1/2,1]
2sin(2x+π/3)∈[1,2]
故f(x)的值域是[1,2]
如果不懂,请Hi我,祝学习愉快!

1年前

6
可能相似的问题
Copyright © 2024 YULUCN.COM - 雨露学习互助 - 16 q. 0.019 s. - webmaster@yulucn.com