Mark M. answered 04/27/19
Retired math prof. Calc 1, 2 and AP Calculus tutoring experience.
Since f"(x) = 36x2 + 10, f'(x) = ∫(36x2+10)dx = 12x3 + 10x + C1.
Since f'(1) = 8, we have 12 + 10 + C1 = 8. So, C1 = -14
Therefore, f'(x) = 12x3 + 10x - 14.
f(x) = ∫f'(x)dx = 3x4 + 5x2 - 14x + C2
Since f(1) = 4, -6 + C2 = 4. So, C2 = 10
f(x) = 3x4 + 5x2 - 14x + 10