# Cosine Integral Formula

Integration of cosine function is an important integral formula in integral calculus; this integral belongs to trigonometric formulae.

The integration of cosine function is of the form

To prove this formula, consider

Using the derivative formula , we have

Integrating both sides of equation (i) with respect to , we have

As we know that by definition integration is the inverse process of derivative, so the integral sign and on the right side will cancel each other, i.e.

__Other Integral Formulas of Cosine Function__**:**

The other formulas of cosine integral with angle of sine is in the form of function are given as

**1. **

**2. **

__Example__**:** Evaluate the integral with respect to

We have integral

Using the formula , we have

__Example__**:** Evaluate the integral with respect to

We have integral

Using the formula , we have