NDA2022MathematicsTrigonometric Ratios & IdentitiesActual
What is the value of ( 5 17 )+ ( 7 17 )+2 ( 11 17 ) ( 17 ) ?
Options
- A0
- B1
- C4 ( 6 17 ) ( 17 )
- D4 ( 11 17 ) ( 17 )
Correct answer
A. 0
Step-by-step solution
Concept: C+ D =2 ( C+D 2 ) ( C-D 2 ) Calculation: Given, ( 5 17 )+ ( 7 17 )+2 ( 11 17 ) ( 17 ) Using identity (i), aligned & 2 ( 5 17 + 7 17 2 ) ( 5 17 - 7 17 2 )+2 ( 11 17 ) ( 17 ) & 2 ( 6 17 ) (- 17 )+2 ( 11 17 ) ( 17 ) & 2 [ ( 6 17 ) ( 17 )+ ( 11 17 ) ( 17 ) ] & 2 ( 17 ) [ ( 6 17 )+ ( 11 17 ) ] aligned Again using (i), aligned & 2 ( 17 ) [2 ( 6 17 + 11 17 2 ) ( 6 17 - 11 17 2 ) ] & 4 ( 17 ) ( 2 ) ( 5 34 ) & 4 ( 17 ) 0 ( 5 34 )=0 aligned