Write a value of `int(sinx)/(cos^3x)\ dx`

Explanation

Solution:

`I=\int \frac{\sin x}{\cos ^{3} x} d x`

=`\int \tan x \sec ^{2} x d x`

Let` t=\sec x \Rightarrow d t=\sec x \tan x d x`

=`\int \{tdt} `

=`\frac{\{t}^{2}}{2}+\{c}`

=`\frac{\sec ^{2} \{x}}{2}+\{c} \quad where ...t=\sec \x`