# Math Help - Conceptual Integrations

1. ## Conceptual Integrations

To integrate $\int\sqrt{a^2-x^2}$ you will let x = ...

To integrate $\int\sqrt{x^2-a^2}$ you will let x = ...

To integrate $\int\sqrt{x^2+a^2}$ you will let x = ...

I'm not sure if I'm meant to derive these or just know them. Either way, I'm screwed.

2. Just know them, google 'trigonometric substitution for integration'

3. Originally Posted by Selim
To integrate $\int\sqrt{a^2-x^2}$ you will let x = ...

To integrate $\int\sqrt{x^2-a^2}$ you will let x = ...

To integrate $\int\sqrt{x^2+a^2}$ you will let x = ...

I'm not sure if I'm meant to derive these or just know them. Either way, I'm screwed.
these all lead to trig substitutions.

8. Integration by Trigonometric Substitution