分式最小值?
(X^2-x-5)/(x+2)
参考答案:(x^2-x-5)/(x+2)
=[(x+2)(x-3)+1]/(x+2)
=(x-3)+1/(x+2)
=(x+2)+1/(x+2)-5
≥2-5
=-3
所以最小值是-3
注:题目要限制x>-2
(X^2-x-5)/(x+2)
参考答案:(x^2-x-5)/(x+2)
=[(x+2)(x-3)+1]/(x+2)
=(x-3)+1/(x+2)
=(x+2)+1/(x+2)-5
≥2-5
=-3
所以最小值是-3
注:题目要限制x>-2