Question

please solve this question friends

Answer 1

it is for tan 75 nd we can do fr 90

Answer 2

For finding the value of tan 75°,
Let A = 45° and B = 30°
So, tan(30+45) = tan30 + tan45/1-tan30tan45
                           = 1/√3+1/1-1/√3
                           = 1+√3/√3/√3-1/√3
                           = 1+√3/√3-1
                           = (1+√3/√3-1)*(√3+1/√3+1)
                           = (√3+1)²/2
                           = 4+2√3/2 = 2+√3
Hence, the value of tan75° is 2+√3.

For finding the value of tan90°, let A = 45° and B = 45°
∴ tan(45+45) = tan45+tan45/1-tan45tan45
                       = 1+1/1-1 = 2/0, which is not defined.
Hence, the value of tan90° is not defined.