NDA2012MathematicsTrigonometric Ratios & IdentitiesActual
If A B=2 , then what is the value of (A+B) (A-B) ?
Options
- A1/3
- B2/3
- C1
- D-1
Correct answer
A. 1/3
Step-by-step solution
( A + B ) ( A - B ) A B- A B A B+ A B Divide N and D by A B , A ~B -1 ~A ~B +1 = 2-1 2+1 = 1 3 .