3(X 2.6)=10.5
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设(x²-1)/(x²+2x)=t则8t+3/t=118t²-11t+3=0(8t-3)(t-1)=0解得t=3/8或t=11.t=3/8(x²-1)/(x
后面的x²+11x-708有误吧!再问:没有题目就这样能不能帮我再答:那我就试试:原式为:1/x2+x+1/x2+3x+2+1/x2+5x+6+1/x2+7x+12+1/x2+9x+20=5
x2+3x2+1=0中的3x2表示什么?再问:已知X2+3X+1=0,求X2+1/X2的值?得数是7。求过程?我打的是X的平方。怎么会出X2、再答:答:因为x≠0,两边都除以x得:x+1/x=-3,两
1/(x²+3x+2)=[(x+2)-(x+1)]/(x+1)(x+2)=1/(x+1)-1/(x+2)同理1/(x²+5x+6)=1/(x+2)-1/(x+3)1/(x²
原式可化为1/(x+1)(x-3)+2/(x-3)((x+2)+3/(x+1)(x+2)=0两边同乘以:(x+1)(x+2)(x-3)得:(x+2)+2(x+1)+3(x-3)=0(x≠-1,x≠-2
等式两边同时乘以(x+3)(x-2)(x+2)就可以去分母了
7/(X2+X)+3/(X2-X)=6/(X2-X),去分母,等式两端同时乘X(X+1)(X-1):7(X-1)+3(X+1)=6(X+1),7X-7+3X+3=6X+6,7X+3X-6X=6+7-3
令t=x2+1(t≥1),则y=3(t-1)+6t=3t+6t-3≥23t•6t-3=62-3,当且仅当3t=6t,即t=2时,函数y=3x2+6x2+1的最小值是62-3.故选D.
原式=9x+6x2-3x+2x2=8x2+6x,当x=-1时,原式=8×(-1)2+6×(-1)=8-6=2.
2x+5x+3+4-x/2+2x+x-2=019x/2=-5x=-19/10检验:带入x是、原式=0
7/(x+x2)-3/(x-x2)=6/(x2-1)两边同乘以x(x+1)(x-1),得7(x-1)+3(x+1)=6x7x-7+3x+3=6x10x-6x=3-74x=-4x=-1经检验x=-1是增
(x²+y²)²+(x²+y²)-6-6=0(x²+y²)²+(x²+y²)-12=0(x²
1/(x2+x)+1/(x2+3x+2)+1/(x2+5x+6)+1/(x2+7x+12)=1/x(x+1)+1/(x+1)(x+2)+1/(x+2)(x+3)+1/(x+3)(x+4)=1/x-1/
建立如下m文件:function xdot=fun(t,x)xdot=zeros(2,1); xdot(1)=-2*x(1)+x(2); xdot(2)=-3*x(1)+
x²+x=0x(x+1)=0x=0x=-13x²-6x+3=0x²-2x+1=0(x-1)²=0x=1再问:用因式分解解题再答:我用的不是因式分解吗?再问:你是
即(x²+4x+4)+(y²-6y+9)=0(x+2)²+(y-3)²=0所以x+2=y-3=0x=-2,y=3所以原式=(4+4)/(4+27)=8/31
手机不行,希望你能看明白吧,主要考察我们对于圆锥曲线跟圆的知识
x2-5x+8=0a=1,b=-5,c=8∴△=b²-4ac=(-5)²-4×1×8=25-32=-7
x2/x1²+x1/x2²=(x1³+x2³)/x1²x2²=(x1+x2)(x1²-x1x2+x2²)/(x1x2)&
3x2+2y2-6x=0x2+y2=1/2(6x-x2)=9/2-1/2(x2-6x+9)=9/2-2-1/2(x-3)2当x=3时,Z最大=4.5