cos(πx 2)的导数-搜答案-搜狗做题网

求cos^3 (3x)的导数?

{cos^3(3x)}'=3cos^2(3X){cos(3x)}'=3cos^2(3X){-sin(3x)}(3x)'=3cos^2(3X){-sin(3x)}3=-9sin(3x)cos^2(3x)

y=cos(2π-x）=cosxy'=(cosx)'=-sinx

f(x)=(1/2^0)·sin(x/2)+(2^0)·cos(2x)f‘(x)=(1/2)·cos(x/2)+(-2)·sin(2x)=(1/2^1)·cos(x/2)+(-2^1)·sin(2x)

这是复合函数求导.设x²＋π/3=t,cost=m,则原函数等价于Y=m²,所以y'=2m×m对t求导×t对x求导=2m×(－sint)×(2x)=2cost×(－sint)×2x

[cos(1+x)]=-sin(1+x)*(1+x)'=-sin(1+x)再问：如果是求cos(1+x^2)的导数？再答：属于复合函数。y=cos(1+x)可以设t=x+1，则dy/dt=-sint,

求cos(x^2)的导数

-2xsin(x^2)

(cos(3x))'=-sin(3x)*(3x)'=-3sin(3x)

cos(3-x)'=-sin(3-x)*(-1)=sin(3-x)

1.将cos(2x-π/3)看成整体√cos(2x-π/3)的导数是1/[2√cos(2x-π/3)]将2x-π/3看成整体cos(2x-π/3)的导数是-sin(2x-π/3)2x-π/3的导数是2

对x求导-sinxy*(xy)'=1(xy)'=x'*y+x*y'=y+x*y'所以y+x*y'=-1/sin(xy)y'=-[1/sin(xy)+y]/x

y'=2cos(2x-π/4)-3sin(3x+π/3)希望可以帮到你,如果解决了问题,请点下面的"选为满意回答"按钮,

y'=[(4x^3+2x)(x^2+2)/(x^4+x^2)-2xln(x^4+x^2)]/[x^2+2]^2=[(4x^3+2x)(x^2+2)-2x^3(x^2+1)ln(x^4+x^2)]/[(

y=cos²(2x-π/3)=[cos(4x-2π/3)+1]/2=(1/2)cos(4x-2π/3)+1/2y'=-(1/2)sin(4x-2π/3)*4=-2sin(4x-2π/3)

cos(nx)的导数为?

d[cos(nx)]=-sin(nx)d(nx)=-nsin(nx)dxd[cos(nx)]/dx=-nsin(nx)

答：y=cos(-2x+π/4)y=cos(2x-π/4)y'(x)=-2sin(2x-π/4)

复合函数求导y'=[cos（sinx）]'=sin(sinx)·（sinx）‘=sin（sinx）·cosx

ln(cos 8θ）的导数

对θ求导是1/cos8θ*（-sin8θ）*8=-8tan8θ解毕~望采纳~一楼不对.楼主注意了

(x*sinx*cosx)'=(1/2xsin2x)'=1/2(sin2x+xcos2x*2)=1/2sin2x+xcos2x

y'=2cos(sin2x)×[cos(sin2x)]'=2cos(sin2x)×[-sin(sin2x)]×(sin2x)'=-sin(2sin2x)×2cos2x=-2cos2xsin(2sin2

y=xsinx(x/2-π/2)cos(x/2+π/2)=-xsin(π/2-x/2)(-sinx/2)=xsinx/2cosx/2=1/2xsinxy'=1/2[sinx+xcosx]