Question

let f(x) denote a polynomial of degree 3. Suppose f(x-2)-f(x)=x²+4x+x and f(1)=9. find the value of f(3)

Answer 1

Answer:

f(3)= -15

Step-by-step explanation:

You just need to plug-in 3 to the equation.

f(x-2)-f(x)=x²+4x+x

f(3-2)-f(3)= 3²+4×3+3

f(1) -f(3)= 9+12+3=24

f(3)=f(1) -24

since it is given that f(1) = 9, we can directly use it.

f(3) = 9 -24 = -15