F'(x) = x - √x dan f(4) = -3

f'(x) = x - √x = x - x^1/2
f(x) = integral (x - x^1/2) dx
f(x) = 1/2 x^2 - 2/3 x^3/2 + C
f(x) = 1/2 x^2 - 2/3 x√x + C
f(4) = 1/2 . 4^2 - 2/3 . 4√4 + C = -3
=> 8 - 16/3 + C = -3
=> C = -11 + 16/3 = -17/3
Jadi
f(x) = 1/2 x^2 - 2/3 x√x - 17/3