x2-1分之x2-2x 1 x 1分之2求值
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(2x+1)/(x^2+1)>0,x^2+1>0,上式变为2x+1>0,2x>-1,∴x>-1/2.(2x+1)/(x^2+2)>1,x^2+2>0,两边都乘以x^2+2,得2x+1>x^2+2,∴x
(x²+x)²-(x²+x)-2=(x²+x)²-2(x²+x)+(x²+x)-2=[(x²+x)²-2(x&
第一天题答案是x+3分之x-2
x^2-3x+2=0(x-2)(x-1)=0x=2或x=1当x=2时x^2+1/x^2=2^2+1/2^2=4+1/4=17/4当x=1时x^2+1/x^2=1^2+1/1^2=1+1=2
已知:(x²+1)/x=x²/x+1/x=x+1/x所以:x²+1/x²=x²+1/x²+2-2=(x+1/x)²-2
X1+X2=-B/A=2X1*X2=C/A=1/2求得X1=1+根号2或者X1=1-根号2从而求出X2的值X1/X2+X2/X1=(X1*X1+X2*X2)/(X1X2)=6
=2x/(x+2)(x-2)-(x+2)/(x+2)(x-2)=[2x-(x+2)]/(x+2)(x-2)=(2-x)/(x+2)(x-2)=-1/(x+2)
x1+x2=5;x1x2=1;(1)x1/x2+x2/x1=(x1²+x2²)/(x1x2)=((x1+x2)²-2x1x2)/(x1x2)=(25-2)/1=23;(2
原式=(x+1)/(x-1)-x(x-2)/(x+1)(x-1)÷(x-2)(x+1)/(x+1)²=(x+1)/(x-1)-x/(x-1)=(x+1-x)/(x-1)=1/(x-1)请好评
这道题,谁要是能理解是什么式子,就已经是大神了
其实第n项=n*(n+1)=n^+n;则前n项的和为n(n+1)(2n+1)/6+n(n+1)/2=n(n+1)(n+2)/3.题目:带入即可得2010/3
x²+2x+1=10(x+1)²=10x+1=3或x+1=-3所以x=2或x=-4【(x²+4)/x-4】÷【(x²-4)/(x²+2x)】=【(x&
(x^2-2x+1)/(x^2-1)+1/(x+1)=(x-1)^2/(x+1)(x-1)+1/(x+1)=(x-1)/(x+1)+1/(x+1)=x/(x+1)=1-根2分之一
n(n+1)分之1=nx(n+1)分之n+1-n=n分之1-(n+1)分之1
发照片呀再问:请原谅手机不行再问:请帮我一下,谢谢。再答:看不明白再问:你写出来就行了的再答: 再答:是这样吗再问:嗯,麻烦把过程写详细点再答:我说题目对不再问:是的再问:对的再问:还有一个
你确认不是二分之一.==
由韦达定理得:x1+x2=2ax1x2=a^2-2a+2因此有:x1^2+x2^2=(x1+x2)^2-2x1x2=4a^2-2a^2+4a-4=2a^2+4a-4=2即a^2+2a-3=0(a+3)
发现的规律是-1/[n*(n+1)]=-1/n+1/(n+1)所以(-1X2分之1)=-1+1/2(-2分之1X3分之1)=-1/2+1/3以此类推(-2007分之1X2008分之1)=-1/2007
提取公因式(x1-x2)原式=(x1-x2)]1-4/x1x2]
x1+x2=4x1x2=-1(x1+x2)^2/(1/x1+1/x2)=(x1+x2)^2*x1x2/(x1+x2)=x1x2*(x1+x2)=-4