BITSAT2010MathematicsTrigonometric EquationsActual
If (12 ^2 -31 coses +32=0 ), then the value of ( ) is
Options
- A( 3 5 ) or 1
- B( 2 3 ) or ( -2 3 )
- C( 4 5 ) or ( 3 4 )
- D( 1 2 )
Correct answer
A. ( 3 5 ) or 1
Step-by-step solution
( aligned & 12 ^2 -31 cosec +32=0 & 12 ( cosec ^2 -1 )-31 cosec +32=0 & 12 cosec ^2 -31 cosec +20=0 & 12 cosec ^2 -16 cosec -15 cosec +20=0 & (4 cosec -5)(3 cosec -4)=0 & cosec = 5 4 , 4 3 ; = 4 5 , 3 4 aligned )