ExamBro
ExamBro
MHT CET · Maths · Trigonometric Equations

If \(\frac{\sin (A+B)}{\sin (A-B)}=\frac{\cos (C+D)}{\cos (C-D)}\), then \(\tan A \cot B=\)

  1. A \(\cot C \cot D\)
  2. B \(-\tan C \tan D\)
  3. C \(\tan C \tan D\)
  4. D \(-\cot C \cot D\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(-\cot C \cot D\)

Step-by-step Solution

Detailed explanation

\(\frac{\sin (A+B)}{\sin (A-B)}=\frac{\cos (C+D)}{\cos (C-D)}\)
\(\therefore \frac{\sin (A+B)+\sin (A-B)}{\sin (A+B)-\sin (A-B)}=\frac{\cos (C+D)+\cos (C-D)}{\cos (C+D)-\cos (C-D)}\)
\(\therefore \frac{2 \sin A \cos B}{2 \cos A \sin B}=\frac{2 \cos C \cos D}{-2 \sin C \sin D}\)
\(\quad \tan A \cot B=-\cot C \cot D\)