来自郭明金的问题
【f(x)=3sin^2+2sinxcosx+cos^2化简】
f(x)=3sin^2+2sinxcosx+cos^2化简
1回答
2020-06-15 15:38
【f(x)=3sin^2+2sinxcosx+cos^2化简】
f(x)=3sin^2+2sinxcosx+cos^2化简
首先运用sin^2+cos^2=1得
f(x)=2sin^2+2sinxcosx+1
又根据二倍角公式2sin^2=1-cos2x2sinxcosx=sin2x
f(x)=sin2x-cos2x+2=√2(sin2xcosπ/4-cos2xsinπ/4)+2
=√2sin(2x-π/4)+2
回答完毕!如有不懂继续追问这题属于基本化简题熟练运用二倍角公式及和差公式注意多练习分给我哈~