sinxsin2xsin3x的n阶导数

贾侵券2618Sinxsin2x的周期是多少? -
阎泳奚18925142599 ______ F(x)=sinxsin2x的周期为2π

贾侵券2618求函数y=sinxsin2x的值域 -
阎泳奚18925142599 ______ y=sinxsin2x=2[(sinx)^2] cosx=2[1-(cosx)^2]cosx 令cosx=t (-1≤t≤1) y=2(1-t^2)t=2t-2t^3 y'=2-6t^2 -1≤ t < -√3/3,y'<0,y单调递减, y(-1)=0 t =-√3/3,y'=0,y折点 y(-√3/3) = - 4√3/9 - √3/3< t < √3/3,y'>0,y单调递增 t =√3/3,y'=0,y折点 y(√3/3) = 4√3/9 √3/3< t < 1,y'<0,y单调递减 y(1)=0 所以值域为y ∈ [ - 4√3/9, 4√3/9 ]

贾侵券2618求函数y=sinxsin2x的值域 -
阎泳奚18925142599 ______[答案] y=sinxsin2x=2[(sinx)^2] cosx=2[1-(cosx)^2]cosx令cosx=t (-1≤t≤1)y=2(1-t^2)t=2t-2t^3y'=2-6t^2-1≤ t解析看不懂?免费查看同类题视频解析查看解答

贾侵券2618sinxsin2xsin3x的积分怎么求啊 -
阎泳奚18925142599 ______ 三角函数积化和差

贾侵券2618SinXsin2X的最值是什么 -
阎泳奚18925142599 ______[答案] y=sinx*sin2x =sinx*2sinx*cosx =2sinx^2*cosx =2*(1-cosx^2)*cosx u=cosx,u的范围[-1,1] y=2u-2u^3 y'=2-6u^2=0 ==>u^2=1/3==>u=根号3/3,或者-根号3/3 u=根号3/3时,y最大u=-根号3/3,y最小分别求出即可....

贾侵券2618微分方程求:y''+y=sinxsin2x -
阎泳奚18925142599 ______[答案] y''+y=sinxsin2x=(1/2)(cosx-cos3x)y''+y=0特征方程r^2+1=0r1=i r2=-iy=C1cosx+C2sinx设y''+y=sinxsin2x特解y=C1(x)sinx+C2cos3xy'=C1'(x)sinx +C1(x)cosx -3C2sin3xy''=C1''(x)sinx+2C1'(x)cosx-C1(x)sinx -9C2co...

贾侵券2618sinx+sin2x+...+sin(nx)=? -
阎泳奚18925142599 ______ sinx+sin2x+...+sin(nx)=sin(n*x/2)*sin((n+1)*x/2)/sin(x/2) cosx+cox2x+...+cos(nx)=sin(n*x/2)*cos((n+1)*x/2)/sin(x/2) 假设sinx+sin2x+...+sin(nx)=sin(n*x/2)*sin((n+1)*x/2)/sin(x/2)成立 则sinx+sin2x+...+sin(nx)+sin(n+1)x=sin(n*x/2)*sin((n+1)*x/2)/sin(x/2)...

贾侵券2618如何求y=sinx*sin2x*sin3x的二阶导数sinx,sin2x ,sin3x 都分别为一个整体 * 表示乘 -
阎泳奚18925142599 ______[答案] y=sinxsin2xsin3x =-1/2(cos(x+2x)-cos(x-2x))sin3x =-1/2sin3xcos3x+1/2sin3xcosx =-1/4sin6x+1/4(sin(3x+x)+sin(3x-x) =-1/4sin6x+1/4sin4x+1/4sin2x y'=-1/4cos6x*6 +1/4cos4x*4+1/4cos2x*2 =-3/2cos6x+cos4x+1/2cos2x y''=3/2sin6x*6-sin4x*4-1/2sin2x*2 ...

贾侵券2618sinx*cosx*sin2x 化简此式 -
阎泳奚18925142599 ______[答案] sinxcosxsin2x =(1/2)*2sinxcosxsin2x =(1/2)sin2xsin2x =(1/2)sin²2x=(1/2)(1-cos4x)/2=(1-cos4x)/4

贾侵券2618sin2nx/sinx dx 的不定积分 -
阎泳奚18925142599 ______[答案] sin2nx=sin(2n-1)xcosx+cos(2n-1)xsinx=1/2(sin2nx+sin(2n-2)x)+cos(2n-1)xsinx∴∫(sin2nx/sinx)dx=1/2∫(sin2nx+sin(2n-2)x)/sinxdx+∫cos(2n-1)xdx∴1/2∫(sin2nx/sinx)dx=1/2∫(sin(2n-2)x)/sinxdx+∫cos(2n-1)x...