[6x^4+(x^2-2)(3x^2-2)+(-X^2+2)(x^2-2)]÷(-2x)^2求值 ,其中x=-1/2用简便算法,不要硬算
热心网友
[6x^4+(x^2-2)(3x^2-2)+(-X^2+2)(x^2-2)]÷(-2x)^2=[6x^4+(x^2-2)(3x^2-2-X^2+2)]÷(-2x)^2=[6x^4+(x^2-2)(2x^2)]÷(-2x)^2=[6x^4+2x^4-4x^2]÷(-2x)^2=(8x^4-4x^2)÷(4x^2)=2x^2-1.所以,当x=-1/2时,原式=2*(-1/2)^2-1=1/2-1=-1/2.
热心网友
[6x^4+(x^2-2)(3x^2-2)+(-x^2+2)(x^2-2)]÷(-2x)^2={6x^4+(x^2-2)[3x^2-2-x^2+2]}÷4x^2=[6x^4+2x^2(x^2-2)]÷4(x)^2=(8x^4-4x^2)÷4x^2=2x^2-1x=1/2代入原式=2*(1/2)^2-1=-1/2
热心网友
[6x^4+(x^2-2)(3x^2-2)+(-X^2+2)(x^2-2)]÷(-2x)^2=-1/2
热心网友
[6x^4+(x^2-2)(3x^2-2)+(-x^2+2)(x^2-2)]÷(-2x)^2={6x^4+(x^2-2)[2x^2+(x^2-2)]-(x^2-2)^2}÷(-2x)^2=[6x^4+2x^2(x^2-2)]÷4(x)^2=(8x^2+4x^2)÷4x^2=2x^2-1=(1/2)-1=-1/2