NDA2012MathematicsTrigonometric Ratios & IdentitiesActual
If A= 2 5 and B= 1 10 where A and B are acute angles, then what is A + B equal to?
Options
- A135^
- B90^
- C75^
- D60^
Correct answer
A. 135^
Step-by-step solution
A = 2 5 A= 1- ^2 A = 1- 4 5 = 1 5 B= 1 10 B = 1- ^2 ~B = 3 10 (A+B)= A B+ A B aligned & = 2 5 1 10 + 1 5 3 10 & = 2 5 2 + 3 5 2 = 5 5 2 = 1 2 aligned aligned ( A + B ) & = 4 ~A + B & =45^ or 135^ . aligned