Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Inverse Trigonometric Functions

Question:

If $\frac{\sin A}{\sin C}=\frac{\sin(A-B)}{\sin(B-C)}$, then the sides of ΔABC are in:

Options:

A.P.

G.P.

H.P.

None of these

Correct Answer:

None of these

Explanation:

$\sin A . \sin (B - C) = \sin C \sin(A - B)$

$⇒ \sin(B + C) . \sin(B -C) = \sin(A - B) \sin(A + B) ⇒ \sin^2 B - \sin^2 C = \sin^2 A - \sin^2 B$

$⇒ a^2, b^2 c^2$ are in A.P. (using sin rule)