Math- Trigonometric Identities

Question

Prove that tan(45+x) is identical to 2tan(45-x)

 

Please show all your working 

 

Thanks in advance for your help!

Answer 1

tan (45°+x) = 2tan (45°-x) is NOT an identity.

 

For example, if x = 15°, then tan(45°+x) = tan60° = √3 ≈ 1.7

 

                                        But   2tan(45°-x) = 2tan30° = 2(1/√3)

 

                                                                                           ≈ 1.15