Question

4.已知函数f(x) =3x²-5x+2,求f(a)+f(3)的值

4.已知函数f(x) =3x²-5x+2,求f(a)+f(3)的值

Answer 1

f(a)=3a^2-5a+2,f(3)=3*3^2-5*3+2=27+2-15=14
所以f(a)+f(3)=3a^2-5a+2+14=3a^2-5a+16

Answer 2

将a和3带入f（X）即可

Answer 3

f(a)=3a²-5a+2, f(3)=27-15+2=14,
所以 f(a)+f(3)=3a²-5a+2+14=3a²-5a+16