Answer:

Explanation:
First integrate f'(x) so we can find the funtion f(x):
![4\int\limits {x} \, dx =4[(1)/(2) x^2]=2x^2+C=f(x)](https://img.qammunity.org/2023/formulas/mathematics/college/a5pz4b6kawjayj3q4zhnic3tw6wmp0d53x.png)
The initial conditions say that when x = 0, the function equals 5. Let's write that down:

Therefore, the integration constant 'C' must equal 5. This means that our function is:
