Question

f(x) is a cubic polynomial that satisfies f(1)=f(2)=f(3)=4 and f(0)=0. What is the value of f(7)?

Answer 1

f(x) = ax^3 + bx^2 + cx

a+b+c = 4
8a+4b+2c = 4
27a+9b+3c = 4

f(x) = 2x/3 (x^2 - 6x + 11)

f(7) = 84

Answer 2

Thanks Steve!