If 0° ≤ A ≤ 90°, the simplified form of the given

Home » Aptitude » Trigonometry » Question

If 0° ≤ A ≤ 90°, the simplified form of the given expression sin A cos A (tan A – cot A) is

1. 1
2. 1 – 2 sin² A
3. 2 sin² A – 1
4. 1 – cos² A

Correct Option: C

sin A. cos A (tan A – cot A)

= sin A. cos A		sin A	-	cos A
		cos A		sin A

= sin A. cos A			sin² A - cos² A
			sin A . cos A

= sin²A – cos²A
= sin²A – (1 – sin²A)
= sin²A – 1 + sin²A
= 2 sin²A – 1