tan 5pi/8 exact value

Accepted Solution

To solve this exercirse, you must apply the proccedure below:

 1. You need to apply the "Half-angle identity for tangent", which is:


 2. But first, the angle 5π/4 must be expressed as a product of 1/2, as below:


 3. Now, you can susbtitute the angle into the formula:


 π/4 is the reference angle of 5π/4

 4. Then:


 5. When you simplify the expression, you obtain:


 6. Therefore, the answer is: -1-√2