find the equation of f(x)

f''(x)= 2 + x^3 + x^6

f'(x) = 2x + (1/4)x^4 + (1/7)x^7 + c

f(x) = x^2 + (1/20)x^5 + (1/56)x^8 + cx + k

Wasn't there some more information given?