Reciprocal Identities

Reference > Algebra: Trigonometric Identities

Description

sinx=1cscx\sin{x}=\frac{1}{\csc{x}}

cosx=1secx\cos{x}=\frac{1}{\sec{x}}

tanx=1cotx\tan{x}=\frac{1}{\cot{x}}

cscx=1sinx\csc{x}=\frac{1}{\sin{x}}

secx=1cosx\sec{x}=\frac{1}{\cos{x}}

cotx=1tanx\cot{x}=\frac{1}{\tan{x}}


Examples

Example 1

sec(2y)1cos(2y)\sec{(2y)}-\frac{1}{\cos{(2y)}}
1
Use this property: cosx=1secx\cos{x}=\frac{1}{\sec{x}}.
sec2ysec2y\sec{2y}-\sec{2y}

2
Simplify.
00

Done


 

Example 2

4cscx+sinx\frac{4}{\csc{x}}+\sin{x}
1
Simplify  4cscx\frac{4}{\csc{x}}  to  4sinx4\sin{x}.
4sinx+sinx4\sin{x}+\sin{x}

2
Simplify.
5sinx5\sin{x}

Done