已知x x的负一次方=3,求x的3次方加x的负三次方-搜答案-百度作业网

1/(x+y)=10x+y=1/10(x+y)²=1/100x²+y²+2xy=1/100①1/(x-y)=6x-y=1/6(x-y)²=1/36x²

X+X的负一次方=3X+1/X=3（1）（X的二分之一次方+X的负二分之一次方）平方=X+1/X+2=5X的二分之一次方+X的负二分之一次方=正负根号5(2)(X+1/X)^2=X^2+1/X^2+2

已知x+x的负一次方=4,求x的平方+x的负二次方的值由已知：x+1/x=4可得：（x+1/x)^2=16x^+1/x^2=16-2=14

1.x²+1/x²=x²-2+1/x²+2=(x-1/x)²+2=6²+2=382.4x-5≠0∴x≠5/4当x=四分之三时原式=1+(3/

(x+1/x)²=5x²+1/x²+2=5x²+1/x²=5-2x²+1/x²=3即x²+x-²=3

为方便起见,x的-1次方写作1/x,实际是一样的.x+1/x=-3x⁴+1/x⁴=(x²+1/x²)²-2=[(x+1/x)²-2]&#

x+x^-1=m两边平方x^2+2+x^-2=m^2x^2+x^-2=m^2-2

答：a-1/a=1(a²+1/a²-3)/(a^4-1/a^4)=[(a-1/a)²+2-3]/(a^4-1/a^4)=(1+2-3)/(a^4-1/a^4)=0

x^2+4x+1=0(x+2)^2=3x=-2±√3x^2+1/x=(-2+√3)^2+1/(-2+√3)=7-4√3-2-√3=5-5√3,或x^2+1/x=(-2-√3)^2+1/(-2-√3)=

x+1/x=3(x+1/x)^2=9x^2+1/x^2+2=9x^2+1/x^2=7x^2+1/x^2-2=7-2(x-1/x)^2=5x-1/x=±√5x^2-1/x^2=(x+1/x)(x-1/x

x+1/x=3x²+1/x²+2=9x²+1/x²=7x²+1/x²-2=5(x-1/x)²=5x-1/x=±√5x²-

（x+x负一次方）=9x的平方加x的负二次方+2=9x的平方加x的负二次方=7

x^2-4x+1=0x-4+1/x=0x+1/x=4x^2+1/x^2=(x+1/x)^2-2=4^2-2=16-2=14

x+1/x=M(x+1/x)^2=M^2x^2+2+1/x^2=M^2x^2+1/x^2=M^2-2

因为x+x^(-1)=a两边平方得：x²+2*x*x^(-1)+x^(-2)=x²+2+x^(-2)=a²所以x²+x^(-2)=a²-2再平方得：x

X+X\1=A(X+X\1)的平方=A的平方x的二次方+x的负二次方的值=A的平房-2

反函数的问题f^-1(x)=(x-1)/3f^-1(x+1)=x/3

已知x+1/x=-3那么(x+1/x)^4=x^4+4*x^2+6+4/x^2+1/x^4=（-3）^4=81其中4x^2+4/x^2=4(x^2+1/x^2)=4×[(x+1/x)^2-2×x×1/

(x+1/x)=3两边同时平方得：x^2+1/x^2+2=9所以x^2+1/x^2=9-2=7

x+1/x=31.[x^(1/2)+x^(-1/2)]^2=x+2+1/x=3+2=5x^(1/2)+x^(-1/2)=5^(1/2)2.x^2+x^(-2)=(x+1/x)^2-2=9-2=73.x