7-3  ʹsymsַ顣
⣺Ȼ6-2еı׼ʽEnterȷϡ
>> syms a b c x
>> f = sym('a*x^2 + b*x + c')
f =
a*x^2 + b*x + c
>> g=f^2+4*f-2
g =
 (a*x^2+b*x+c)^2+4*a*x^2+4*b*x+4*c-2
>>
