y=2sin(2x 排 3) b-搜答案-拍题作业网

sinx的周期是2pai,sin3x的周期是三分之二pai,sin5x的周期是五分之二pai取其最小公倍数,则y的周期是2pai.

x=0:0.01:1;y=0;fori=1:20y=y+sin(i*x);endplot(y);

你用积化和差公式一套,然后就能看出它的最小正周期来的.应该是1pi

(x/a)cosθ+(y/b)sinθ=1[(x/a)cosθ+(y/b)sinθ]^2=1(x/a)sinθ-(y/b)cosθ=1[(x/a)sinθ-(y/b)cosθ]^2=1[(x/a)co

y=2sin²B+cos((2π/3)-2B)=(1-cos2B)-1/2cos2B+√3/2sin2B=(-3/2cos2B+√3/2sin2B)+1=√3(1/2sin2B-√3/2co

sin(2a+b)=3sinbsin[(a+b)+a]=3sin[(a+b)-a]sin(a+b)cosa+cos(a+b)sina=3[sin(a+b)cosa-cos(a+b)sina]sin(a

左边=(sinxcosy+cosxsiny)(sinxcosy-cosxsiny)=sin²xcos²y-cos²xsin²y=sin²x(1-sin

2sin2(2x+∏/3)

dy/dx相当于对x进行求导：dy/dx=y'=2x*cos[sin(x^2)]*cos(x^2)由于：sinx=cosx,sin(x^2)=2x*cos(x^2)

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

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)/

-2k=cos2x-cos2y=[2(cosx)^2-1]-[2(cosy)^2-1]=2[(cosx)^2-(cosy)^2]cos^2x-cos^2y=-k

y=4－3sin（2x－π/3)令f(x)=3sin(2x-π/3)则f(x)的值域是【-3,3】所以y的最大值是4-(-3)=7y的最小值是4-3=1当y取最大值时2x-π/3=2kπ+3π/2所以

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

解y=asin(3/x)+bcos²xy‘=[asin(3/x)+bcos²x]'=[asin(3/x)]'+(bcos²x)'=acos(3/x)(3/x)'+2bco

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

y=sin(x^2),求dy/d(x^3)

dy/d(x^3)=(dy/dx)/(d(x^3)/dx)=cosx/3(x^2)

cos²x+sin²x=1∴cos²x=1-sin²xy=cos²x-2sinx+b=1-sin²x-2sinx+b设t=sinx,∵0≤x