What is the value of [(cos 7A + cos 5A) ÷ (sin 7A – sin 5A)]?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. cot A
[(cos 7A + cos 5A) ÷ (sin 7A – sin 5A)]
= (2 cos 6A cosA)/(2 cos6A sinA)
= cos A/sin A = cot A