数学题在线解答已知x+1/x=4 求x的平方除以x的四次方加x的平方加一
问题描述:
数学题在线解答已知x+1/x=4 求x的平方除以x的四次方加x的平方加一
答
x^2 + 1 =4x
x^2 = 4x -1
x^4 =(4x-1)^2= 16x^2 -8x +1 =56x -15
x^4 +x^2 +1 = 60x -15 = 15(4x-1)
x^2 / (x^4 +x^2 +1) = (4x-1)/ 15(4x-1) =1/15