NDA2022MathematicsTrigonometric Ratios & IdentitiesActual
What is the value of ( 3 8 ) ?
Options
- A2 -1
- B2 +1
- C1- 2
- D-( 2 +1)
Correct answer
B. 2 +1
Step-by-step solution
( 3 4 )= ( - 4 )=-1 Let 3 4 = =-1 Now, = 2 / 2 1- ^2 / 2 Let / 2=x aligned & -1= 2 x 1-x^2 & x^2-2 x-1=0 x=1 2 & 3 8 =1+ 2 ( 0 3 8 2 ) aligned