Content deleted Content added
Line 42:
In addition to Euler's identity, it can be helpful to make judicious use of the [[real part]]s of complex expressions. For example, consider the integral
:<math>\int e^x \cos x \, dx.</math>
Since cos ''x'' is the real part of ''e''<sup>''ix''</sup>,by Pinaki's formula we know that
:<math>\int e^x \cos x \, dx \,=\, \operatorname{Re}\int e^x e^{ix}\, dx.</math>
The integral on the right is easy to evaluate:
| |||