AP EAMCET2015MathematicsTrigonometric Ratios & Identities
If (120^ - ) (120^ + )= 1 3 , then is equal to
Options
- An 3 + 18 , n Z
- Bn 3 + 12 , n Z
- Cn 12 + 12 , n Z
- Dn 3 + 6 , n Z
Correct answer
A. n 3 + 18 , n Z
Step-by-step solution
We have given, (120^ - ) (120^ + )= 1 3 Since, we know aligned & (120^ - ) (120^ + )= 3 & 3 = 1 3 3 = 6 & 3 =n + 6 & = n 3 + 18 , n Z aligned