The problem wishes us to integrate
![sec^(2)(x)](https://img.qammunity.org/2023/formulas/advanced-placement-ap/high-school/gu54934jyqqw0qdedp4rh7um3ubpcs1xv3.png)
-However, we know based on the derivation of tan (x)
![(d)/(dx)tan(x)=sec^(2) (x)](https://img.qammunity.org/2023/formulas/advanced-placement-ap/high-school/gx1feqcudmuw0bxwl5sfimx0wuej2jc3tj.png)
Bascially integration is the reversal of the derivation:
Thus
![\int\limits^a_b {sec^(2)(x)} \, dx =tan(x) +C](https://img.qammunity.org/2023/formulas/advanced-placement-ap/high-school/wk82glpcwjte9e1cv1cegaygpxcxymeapo.png)
Since there are no bounds, we must add a constant 'C' as we don't know if there was an initial value
Hope that helps!