NDA2019MathematicsTrigonometric Ratios & IdentitiesActual
Paragraph: It is given that ( - )=a, ( - )=b Question: What is ( - ) equal to?
Options
- Aa b+ 1-a^2 1-b^2
- Ba b- 1-a^2 1-b^2
- Ca 1-b^2 -b 1-a^2
- Da 1-b^2 +b 1-a^2
Correct answer
A. a b+ 1-a^2 1-b^2
Step-by-step solution
Given, ( - )= a ( - )= 1-a^2 aligned & ( - )= b ( - )= 1-b^2 & ( - )= ( - -( - )) & = ( - ) ( - )+ ( - ) ( - ) & =(b)(a)+ 1-b^2 1-a^2 & =a b+ 1-a^2 1-b^2 aligned