Final answer:
To find the function f given its derivative f'(x) = 1 + 3sqrt(x) and the condition f(4) = 25, we integrate the derivative and use the condition to solve for the integration constant, resulting in f(x) = x + 2sqrt(x)^2 + 13.
Step-by-step explanation:
The question involves finding a function f given its derivative f'(x) = 1 + 3√x and a condition on the function f(4) = 25. To solve this, we integrate the derivative to find the original function. The solution involves first integrating the derivative:
∫ (1 + 3√x) dx = ∫ dx + 3∫ √x dx = x + 2√x2 + C,
where C is the constant of integration. We use the condition f(4) = 25 to solve for C.
f(4) = 4 + 2√(4)2 + C = 4 + 2(2)2 + C = 4 + 2(4) + C = 4 + 8 + C,
which simplifies to 25 = 12 + C, so C = 13. Therefore, our function is:
f(x) = x + 2√x2 + 13.