sin^2x分之cos2x的不定积分

f(x)=2cos2x+sin平方x－4cosx=3cos^2x-4cosx-1=3(cosx-2/3)^2-7/3(1)f(π/3)=3*(cosπ/3)^2-4cosπ/3-1=3*(1/2)^2

把f(x)化成关于cosx的函数f(x)=2(2cos²x-1)+1-cos²x-4cosx=3cos²x-4cosx-1(1)f(60)=-9/4(2)f(x)=3(c

cos2α=1-2sin²αsin²α　=(1-cos2α)/2除以2是这么来的后面就是合并同类项了.再问：麻烦问下这个cos2α=1-2sin²α是什么公式吗？再答：三

f(x)=0.5(1-cos2x)+0.5sin2x+cos2x=0.5+0.5(sin2x+cos2x)=0.5+0.5根号2sin(2x+π/4)f(x)的最小值是（1-根号2)/2

函数f(x)=2sin^2(x+π/4)-√3cos2x-1=-cos(2x+π/2)-√3cos2x=sin2x-√3cos2x=2sin(2x-π/3)1.当x属于R时,函数f(x)的最小正周期T

(1)首先利用降幂公式：f(x)=1-cos(π/2+2x)-根号3cos2x再利用诱导公式：f(x)=1+sin2x-√3cos2x最后是辅助角公式:f(x)=2*(1/2*sin2x-√3/2*c

cos2x/(cosx+sinx)=(cos²x-sin²x)/(cosx+sinx)=(cosx+sinx)(cosx-sinx)/(cosx+sinx)=cosx-sinx求导

看图片吧

f(x)=2cosx+(1-cos2x)/2=(3/2)cos2x+1/2所以最大=3/2+1/2=2最小是-3/2+1/2=-1

3sin^2x+cos^2x=2sin^2x+sin^2x+cos^2x=2sin^2x+1=2+2sin^2x-1=2-cos2x

cos2x+cos(x+π/3)+sin(x+π/6)+3sin^2x=cos2x+1/2*cosx-根号3/2*sina+根号3/2*sinx+1/2*cosx+3sin^2x=cos2x+cosx

2cos2x+sin^2x=2(cos^2x-sin^2x)+sin^2x=2cos^2x-sin^2x=3cos^2x-1

f(x)=2cos2x+sin^2x-4cosx=2(cosx)^2+(sinx)^2-4cosx=1+(cosx)^2-4cosx=(cosx-2)^2-3=(cosx-2+√3)(cosx-2-√

原式=lim(x→0)sin(x/2)+lim(x→0)cos2x=0+1=1再问：不好意思是求Lim(x→0)[sin（x/2）+cos2x]^(1/x)的极限再答：解:原式=lim(x→0)e^[

sin^4x+cos^4x-2cos2x=(sin^2x+cos^2x)^2-2*sin^2x*cos^2x-2cos2x=1-(sin(2x)^2)/2-2*cos(2x)=3/4+1/4*cos(

等一下再答：

因为sin^2(X)+cos^2(X)=1所以原式=1-cos^2（x）-cos^2（x）=1-2cos^2(x)=-(2cos^2(x)-1)=-cos2x

sin(x/2)的周期是4pi,cos2x的周期是pi,sin(x/2)+cos2x的周期是其最小公倍数,自然是4pi

f(x)=(1+cos2x+8sin^2x)/sin2xf(x)=(1+2cosx²-1+8sin²x)/2sinxcosxf(x)=(cosx²+4sin²x

sin2x+sin(π-x)/2cos2x+2sin^2x+cos(-x)=sin2x+sin(x)/2cos2x+2sin^2x+cos(x)=(2cosxsinx+sinx)/2cos²