f0到πx*f(sinx)dx

令u=π/2-x则x=π/2-u原积分=∫(π/2→0)f(sin(π/2-u))/[f(sin(π/2-u))+f(cos(π/2-u))]d(π/2-u)=-∫(π/2→0)f(cosu)/[f(

记A＝∫(0到π)x(sinx)^6dx,换元x＝π-t,则A＝∫(0到π)π(sint)^6dt－∫(0到π)t(sint)^6dt,所以A＝π/2×∫(0到π)(sinx)^6dx.(sinx)^

移到一边,积分限内：(x-π/2)f(sinx)令x-π/2=ppf(Cosp),P积分限为-π/2至π/2,p为奇函数,f(Cosp)为偶函数,pf(Cosp)为奇函数,对称区间中积分为0.再问：你

f'(x)=cosx+f(x)f(0)=0解如上微分方程得：f(x)=(sinx+cosx)/2-(1/2)e^x

我算算再问：好的，谢了再答：做出来了，给你传个图再问：好的，，呵呵再答：再问：线性微分方程y^（4）-y=0通解为再问：这个呢再答：y^4-y=0的通解？再问：对啊再问：帮帮忙再答：你题没写错吧？再问

算嘛再答：再问：额，这样额再问：再问：那如果是这样的也是算？再答：你那是大几的题目啊再问：大一额再答：问你们数学老师去

证明：由题意可得∫f(sinx)dx求导可得f(sinx)∫f(cosx)dx求导可得f(cosx)因为f(x)一定,当x在（0,π/2）时f(sinx)在f(0~1）之间取值同理f(cosx)也在f

被积函数以2π为周期,所以F(x)＝∫(x→x+2π)sinx(e^sinx)dx＝∫(0→2π)sinx(e^sinx)dx＝∫(-π→π)sinx(e^sinx)dx＝∫(-π→0)sinx(e^

I=∫[0,π/2]f(cosx)dx换元,令u=π/2-x,dx=(﹣1)du=∫[π/2,0]f(sinu)(-1)du=∫[0,π/2]f(sinu)du=∫[0,π/2]f(sinx)dx

(1)∫1/[x(x-1)]dx=∫[1/(x-1)-1/x]dx=ln|x-1|-ln|x|+C=ln|(x-1)/x|+C(2)∫cos2x/(sinx+cosx)dx=∫(cosx-sin

左边=-cosπ+cos0=2右边=2(-cosπ/2+cos0)=2原式成立再问：是f(sinx),不是sinx再答：抱歉，没仔细看题呵。令x=(π/2)-t则∫(0,π/2)f(sinx)dx=∫

记sinx=t∫cosxf(sinx)dx=∫f(sinx)dsinx=∫f(t)dt=F(t)+C=F(sinx)+C

证明：令x=π-t,则x由0到π,t由π到0,dx=-dt原式记为I则I=-（积分区间π到0）∫(π-t)f(sin(π-t)dt=-(积分区间π到0）∫(π-t)f(sin(t)dt=(积分区间0到

令u=π-x,du=-dx,u：π--->0,则∫[0--->π]xf(sinx)dx=-∫[π--->0](π-u)f(sin(π-u))du=∫[0--->π](π-u)f(sinu)du=π∫[

证明：因为∫(0→π)f(sinx)dx=∫(0→π/2)f(sinx)dx+∫(π/2→π)f(sinx)dx令x=π-t则当x=π/2时t=π/2当x=π时t=0所以∫(π/2→π)f(sinx)

∫(π/2→π)(sinx+1/x)dx=[-cosx+ln|x|]|(π/2→π)=[-cosπ+ln(π)]-[-cos(π/2)+ln(π/2)]=1+ln(π)-0-[ln(π)-ln(2)]

∫上2下0；f(x)dx=∫上2下π/2；f(x)dx+∫上π/2下0；f(x)dx=∫上2下π/2；1dx+∫上π/2下0；sinxdx=x│上2下π/2-cosx│上π/2下0=（2-π/2）-（

设x=π-y,dx=-dy当x=0,y=π当x=π,y=0∫(0→π)xf(sinx)dx=-∫(π→0)(π-y)f(sin(π-y))dy=π∫(0→π)f(siny)dy-∫(0→π)yf(si