Question

how to find the value of tan pi/8

Answer 1

Step-by-step explanation:

After ans reply for it.....

Answer 2

Answer:

So,  tan π/8 = √2 - 1

Step-by-step explanation:

let Ф = π/8

2Ф = π/4  

   tan 2Ф = 1  = 2 tan Ф / [ 1 - tan² Ф ]

  1  - tan² Ф = 2 tan Ф

  tan² Ф + 2 tan Ф - 1 = 0

  tan Ф  =  1/2 [ -2 +- √(4 +4) ]  = -1 +- √2

  tan π/8 is > 0 So,  tan π/8 = √2 - 1