ab为实数,满足a^3-3a^2+5a=1 b^3-3b^2+5b=5,求a+b

2024-11-07 02:42:04
推荐回答(1个)
回答(1):

设f(x)=x^3-3x^2+5x
f'(x)=3x^2-6x+5
△=36-4*3*5