AP EAMCET2006MathematicsTrigonometric Ratios & Identities
cosec 15^ + 15^ is equal to :
Options
- A2 2
- B6
- C2 6
- D6 + 2
Correct answer
D. 6 + 2
Step-by-step solution
cosec 15^ + 15^ = 2 ( 15^ + 15^ ) 2 15^ 15^ = 2 ( 45^ 30^ - 45^ 30^ + 45^ 30^ + 45^ 30^ ) 30^ =4 [ 3 2 2 - 1 2 2 + 1 2 2 + 1 2 2 ]=4 3 +1 2 2 =( 3 +1) 2 = 6 + 2