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Aptitude · Q253

Trigonometry

Competitive Exams · Aptitude · question 253

Q253

If sin(A + B) = 3 2 and tan(A - B) = 1 3 , then (2A + 3B) is equal to.

If sin(A + B) = and tan(A - B) = , then (2A + 3B) is equal to.
A.
120°
B.
135°
Answer
C.
130°
D.
125°

Answer: Option B

Solution

Answer: Option B
Solution:
sin(A + B) =
sin(A + B) = sin60°
A + B = 60° . . . . . . . .(i)
tan(A - B) =
tan(A - B) = tan30°
A - B = 30° . . . . . . . . (ii)
Equation (i) adding equation (ii)

A = 45°
B = 15°
(2A + 3B)
= (2 × 45° + 3 × 15°)
= 90° + 45°
= 135°