∫{(x^3)(sin^2) [(x^4) (2x^2) 1]}-搜答案-大师作文网

$∫{(x^3)(sin^2) [(x^4) (2x^2) 1]}$

∫sin^3(x)cos^2(x)dx=∫sin^2(x)cos^2(x)sin(x)dx=-∫sin^2(x)cos^2(x)dcos(x)=∫[cos^2(x)-1]cos^2(x)dcos(x)

1和3等价无穷小替代,sinxx,答案为2/5和w,第二题用洛必达法则,答案cosa,过程应该会写吧,我用手机回答的,输入不方便,请谅解

原式=1/3*∫sin(3x+2)d(3x+2)=-1/3*cos(3x+2)

望采纳

原式等于：∫[1-cos^2(x)]/cos^3(x)dx=∫dx/cos^3(x)-∫dx/cos(x)=(secxtanx+ln|secx+tanx|)/2-ln|secx+tanx|+C

∫[cos^3(x)]/[sin^2(x)]dx=积分:(cos^2x)/(sin^2x)dsinx=积分:(1-sin^2x)/sin^2x)dsinx=积分;1/sin^2xdsin^2x-积分1

∫dx/sin^2(2x-3)=?

由于dx=d(2x-3)/2所以Int(dx/sin(2x-3)^2)=Int(d(2x-3)/sin(2x-3)^2)/2=-cot(2x-3)/2+C

∫sin^3(x)cos^2(x)dx=

把一个sin(x)拿出来∫sin^3(x)cos^2(x)dx=-∫sin^2(x)cos^2(x)d(cos(x))=-∫(1-cos^2)cos^2(x)d(cos(x))=-∫cos^2-cos

∫(cos^3x/sin^2x)dx

∫(cos^3x/sin^2x)dx=∫[(1-(sinx)^2]/(sinx)^2dsinx=∫[1/(sinx)^2-1]dsinx=-1/sinx-sinx+C

f(x)=sin(π-x)cos(3π/2+x)+sin(π+x)sin(3π/2-x)=(sinx)(sinx)+(-sinx)(-cosx)=sinx(sinx+cosx)f'(x)=cosx(s

∫sin(x) cos^2(x)dx

原式=-∫cos²xdcosx=-cos³x/3+C再问：第一步能讲一下为什么吗？再答：dcosx=-sinxdx采纳吧

我知道这个题是个定积分题,请追问我给出积分限.我按我以前做过的同一题给你做吧,积分限是0→π∫[0→π]√(sin^3x-sin^5x)dx=∫[0→π]√[sin³x(1-sin²

f(x)=cos(3x)*cos(2x)+sin(3x)*sin(2x)=cos(3x-2x)=cosxf'(x)=-sinx

先积化和差sin3xsin5x=0.5（cos2x-cos8x）∫sin3xsin5xdx=∫0.5（cos2x-cos8x）dx=0.25sin2x-0.0625sin8x+c

x=0:0.1:2*pi;s=2*sin(x)-sin(2*x)+2/3*sin(3*x)-1/2*sin(4*x)+2/5*sin(5*x);plot(x,s)

sin^4x-sin^2xcos^2x+cos^4x=sin^4x+2sin^2xcos^2x+cos^4x-3sin^2xcos^2x=(sin^2x+cos^2x)^2-3sin^2xcos^2x

换元法?没必要啊显然这是个奇函数而积分限关于原点对称所以原式=0

解∫x³sinx²dx=1/2∫x²sinx²dx²=1/2∫usinudu=-1/2∫ud(cosu)=-1/2[ucosu-∫cosudu]=-1

sin^4x-sin^2xcos^2x+cos^4x=sin^4x+2sin^2xcos^2x+cos^4x-3sin^2xcos^2x=(sin^2x+cos^2x)^2-3sin^2xcos^2x