AP EAMCET202316 May 2023Morning ShiftMathematicsTrigonometric Ratios & IdentitiesActual
^4 8 + ^4 3 8 + ^4 5 8 + ^4 7 8 =
Options
- A1 4
- B3 8
- C3 2
- D3 4
Correct answer
C. 3 2
Step-by-step solution
^4 ( 8 )+ ^4 ( 3 8 )+ ^4 ( 5 8 )+ ^4 ( 7 8 )= ^4 ( 8 )+ ^4 ( 3 8 )+ ^4 ( - 3 8 )+ ^4 ( - 8 )= ^4 ( 8 )+ ^4 ( 3 8 )+ ^4 ( 3 8 )+ ^4 ( 8 )=2 [ ^4 ( 8 )+ ^4 ( 3 8 ) ]=2 [ ( 1- ( 4 ) 2 )^2+ ( 1- ( 3 4 ) 2 )^2 ]= [ ( 1- 1 2 2 )^2+ ( 1+ 1 2 2 )^2 ]= 2 4 [ (1- 1 2 )^2+ (1+ 1 2 )^2 ]= 3 2 ^4 8 + ^4 3 8 + ^4 5 8 + ^4 7 8 = 3 2 .