x² 1 x四次方 1的积分-搜答案-搜搜考试网

x＾4＋（1／x）＾4＝[x^2+（1/x)^2]^2-2*x^2*（1/x)^2=[x^2+（1/x)^2]^2-2=[(x+1/x)^2-2*x*(1/x)]^2-2=[(x+1/x)^2-2]^

x+1/x=3两边平方x²+2+1/x²=9x²+1/x²=7两边平方x⁴+2+1/x⁴=49所以x⁴+1/x⁴

x²-3x+1=0两边同时除以xx-3+1/x=0x+1/x=3两边平方得x²+2+1/x²=9x²+1/x²=7两边再平方得x^4+2+1/x^4=

∵(x^2)/(x^4+1)=1/3∴x^4+1=3x^2∴(x^4)/(x^8+x^4+1)=(x^4)/[(x^4+1)^2-x^4]=(x^4)/[(3x^2)^2-x^4]=(x^4)/(9x

∵x²+x+1=0两边除以x可得x+1+1/x=0x+1/x=-1两边平方可得x²+1/x²+2=1x²+1/x²=-1两边再平方可得x^4+1/x^

1.原式x^4+2x^3+3x^2+2x+1=x^4+2x^2+1+2x^3+x^2+2x=(x^2+1)^2+x^3+x+x^3+x^2+x=(x^2+1)^2+x(x^2+1)+x(x^2+x+1

X+1/X=2(X+1/X)²=X²+2+(1/X)²=4X²+(1/X)²=2(X²+(1/X)²)²=X^4+2+(

原式＝x^8-x^6-10x^4-x^2+1+10x^4=x^8-x^6-x^2+1=x^6(x^2-1)-(x^2-1)=(x^6-1)(x^2-1)=(x^3+1)(x^3-1)(x+1)(x-1

奇函数在对称区间上的积分为0,sin³x/(1+x^4)是一个奇函数,因此可以直接去掉原式=∫[-1→1]3x²dx=x³|[-1→1]=2

答：设t=x的四次方根,x=t^4原式=∫[1/(t^2+t)]d(t^4)=∫[(4t^3)/(t^2+t)]dt=4∫[t^2/(t+1)]dt=4∫[(t+1-1)^2/(t+1)]dt=4∫[

x²+x+1=0x+1+1/x=0x+1/x=-1两边平方得x²+2+1/x²=1x²+1/x²=-1两边平方得x^4+2+1/x^4=1x^4+1/

∫x^(-4)dx=x^(-4+1)/(-4+1)(1到无穷大)=(-1/3)(1/x³)(1到无穷大)x趋于无穷大(-1/3)(1/x³)极限是0x=1,(-1/3)(1/x&s

x^2+3x+1=0x^2+1/x^2=((-3x-1)^1+1)/(-3x-1)=(9x^2+6x+2)/(-3x-1)=(-27x-9+6x+2)/(-3x-1)=7x^4+1/x^4=(x^2+

不能!再答：令m=x的平方，即m的平方+m－1不能因式分解

x^4-11x^2+1=(x^4-2x^2+1)-9x^2=(x^2-1)^2-(3x)^2=(x^2+3x-1)(x^2-3x-1)

x^4+2x+1=x^4-x²+x²+2x+1=x²(x-1)(x+1)+(x+1)²=(x+1)(x³-x²+x+1)

x^5-x^4+x^3-x^2+x-1=x^4(x-1)+x^2(x-1)+(x-1)=(x-1)(x^4+x^2+1)=(x-1)(x^4+2x^2+1-x^2)=(x-1)[(x^2+1)^2-x

x²-2x-1=0x-1/x=2x^2+1/x^2=(x-1/x)^2+2=4+2=6x^4+1/x^4=(x^2+1/x^2)^2-2=36-2=34

x的四次方-7x²-18=(x^2-9)(x^2+2)=(x-3)(x+3)(x^2+2)7(a+b)²-5(a+b)-2=(7a+7b+2)(a+b-1)8x²-26x