y=sin^3(2x-1)-cos3x-搜答案-智慧作业帮

sin（x+y）=sinxcosy+cosxsiny=1/2,sin（x-y）=sinxcosy-cosxsiny=1/3,两式作商得(sinxcosy+cosxsiny)/(sinxcosy-cos

函数y=1-2sin²3x是

倍角公式y=1-2sin²3x=cos6x所以选B

y=sin(3x^2+1)求导

y'=cos(3x^2+1)×(3x^2+1)'=cos(3x^2+1)×6x=6xcos(3x^2+1)

B只有B是f(x)=f(-x)

x,y,z属于(0,派/2)sinx,cosx∈（0,1）对于a>0,b>0,有不等式：开根号下（a^2+b^2)≥根号2*(a+b)/2sin^2x+sin^2y+sin^2z=1cosx=开根号下

1.y=-3cos2x-1-pai/2

y=cosx/(2cosx+1)=(2cosx+1)y=cosx=2ycosx+y=cosxy=(1-2y)cosxy=1/2时0=1/2y不等于1/2

y=2sin(1\2x-π\3)+1

y=2sin[(1/2)x-π/3]+1(1)最小正周期:T=2π/(1/2)=4π.（2）单调性:由2kπ-π/2≦(1/2)x-π/3≦2kπ+π/2,得2kπ-π/6≦(1/2)x≦2kπ+5π

y'=(cos²x)'-(sin3^x)'=2cosx·(cosx)'-cos3^x·(3^x)'=2cosx·(-sinx)-cos3^x·(3^x·ln3)=-sin2x-ln3·cos

已知sin（x+y）=1,求证：tan（2x+3y）=tany证明：sin（x+y）=1所以x+y=2k兀+兀/2K为整数所以tan(2x+3y)=tan(4k兀+兀+y)=tan(兀+y)=tany

sin^2x+cos^2y=1/2∴sin^2x=1/2-cos^2y3sin^2x+sin^2y=3（1/2-cos^2y）+sin^2y=1.5-3cos^2y）+sin^2y又有sin^2y+c

sinx+siny+sinz-sin(x+y+z)=4sin[(x+y)/2]sin[(x+z)/2]sin[(y+z)/2]sinx+siny+sinz-sin(x+y+z)=2sin[(x+y)/

Sinx-siny=2/3cosx-cosy=1/2分别平方得(Sinx-siny)^2=(2/3)^2(cosx-cosy)^2=(1/2)^2展开相加得-2cos(x-y)+2=4/9+1/4-2

对这样的隐函数求导数的时候,就把y看作x的函数,y对x求导就得到dy/dx所以原等式对x求导得到2xy²+x²*2y*dy/dx+siny+x*cosy*dy/dx=0于是化简得到

y=sin²x+2sinxcosx+3cos²xy=(sin²x+cos²x)+2sinxcosx+(2cos²x-1)+1=1+sin2x+cos2

求导：y=3^(sin*1/x)

y=3^[sin(1/x)]y'=3^[sin(1/x)]ln3*cos(1/x)*(-1/x^2)=-ln3*3^[sin(1/x)]*cos(1/x)/x^2

sin^2x+sin^2y-sin^2x*sin^2y+cos^2x*cos^2y=sin^2x-sin^2x*sin^2y+sin^2y+cos^2x*cos^2y=sin^2x*(1-sin^2y

再答：