2y

y²+y-2y²+y-2=(y+2)(y-1)十字相乘法：y2y-1

y(3y^2+8y-3)-6y(3y+2y-1)+9y求导?求偏导?求微分?给题目呀

x-y/x-x+y/y-(x+y)(x-y)/y²y/x=2以上错误,修改如下：y/x=2→y=2x(x-y)/x-(x+y)/y-(x+y)(x-y)/y^2=((xy-y^2)-(x^2+xy))/xy-(x^2-y^2)/y

yy''-(y')^2=y^2y' yy''-(y')^2=y^2y',那么(yy"-y'^2)/y^2=y',注意到y'/y的导数就是(yy"-y'^2)/y^2,所以对等式两边积分得y'/y=y+A(A为常数),那么dy/[(

yy''-(y')^2=y^2y'YY频道7450免费签约秒过直播间设y=xt,则t=y/x,y'=xt'+t代入原方程得xt'+t+t=1/t==>xt'=(1-2t2)/t==>tdt/(1-2t2)=dx/x==>d(1-2t2)/(

y"+y'-2y=2xy"+y'-2y=2x先求y"+y'-2y=0的通r²+r-2=0,r=1或-2y=ce^x+de^(-2x)再求一个特解,设特解为y=ax+b,则y'=a,y"=0代入原式得0+a-2ax-2b=2x可求得

因式分解-y的立方-2y-y-y的立方-2y²-y=-y(y²+2y+1)=-y(y+1)²

微分方程y"-2y'+y=x先求对应齐次方程的特征方程为r″-2r+1=0r1=r2=1齐次方程的通解为Y=e^x(C1+C2x)再求非其次方程的特特解形式为y0=e^(λx)·x^k·(Ax+B)∵P(x)=x=e^(λx)·x∴λ=0不

2y''+y'-y=02y''+y'-y=0特征方程：2r^2+r-1=0根为：-1,1/2y=C1e^(-x)+C2e^(x/2)2y''+y'-y=0的特征方程2r平方+r-1=0（2r-1)(r+1)=0r=-1,1/2通解y=C(1

因式分解(y^2+y)^2-8(y^2+y)+12＝﹙y²＋y－2﹚﹙y²＋y－6﹚＝﹙y－1﹚﹙y＋2﹚﹙y－2﹚﹙y＋3﹚(y^2+y)^2-8(y^2+y)+12=(y^2+y-6)*(y^2+y-2)（y方+y-

(y平方+2y)(y平方+2y+2)+1(y^2+2y)(y^2+2y+2)+1=(y^2+2y)^2+2(y^2+2y)+1把y^2+2y当成一个因数来算=(y^2+2y+1)^2=(y+1)^4

[(x-y)^2-(x+2y)(x-2y)]/y=[（x²-2xy+y²）-（x²-4y²）]/y=（x²-2xy+y²-x²+4y²）/y=（5y²

y'(2y-y')=y^2*(sinx)^2求解,y'(2y-y')/y^2=sin^2(x)2y'/y-(y'/y)^2=sin^2(x)(y'/y)^2-2y'/y+1=1-sin^2(x)=cos^2(x)(y'/y-1)^2=cos

y^2+y-2/y^2+4y+4约分

(y^2)^4y-(-2y)^3y^6=(y^2)^4y-(-2y)^3y^6=y^8*y+8y^3y^6=y^9+8y^9=9y^9

(3y+2)(y-4)-3(y-2)(y-3)=3y^2-10y-8+3y^2+15y-18=6y^2+5y-266(3y+2)(y-4)-3(y-2)(y-3)=3y^2-10y-8-3(y^2-5y+6)=3y^2-10y-8-3y^2

化简y(x+y)+(x+y)(x-y)-x^2y(x+y)+(x+y)(x-y)-x^2=(x+y)(y+x-y)-x^2=(x+y)*x-x^2=xy

方程y''=(1+y'*y')/2y的通解设y′=p,则y′′=pdp/dy,代入原方程得pdp/dy=（1+p²）/(2y).(1)解（1）得p=±√（C1y-1）,（C1是积分常数）∴y′==±√（C1y-1）,（C1是积分常

3y/x*x-y*y+x/x*x-2xy+y*y+6y*y/x*x*x-x*x*y-xy*y+y*y*y等于多少?3y/(x^2-y^2)+x/(x^2-2xy+y^2)+6y^2/(x^3-x^2y-xy^2+y^3)=3y/[(x+y)

不定积分(sin1/y)/y^2∫[(sin1/y)/y^2]dy令u=1/ydu=(-1/y^2)dy原式=∫-sinudu=cosu+C=cos(1/y)+C就等於cos(1/y)。。。