If 3 sin2 A + 4 cos2 A - 3 = 0, then the value of cot A (where 0 ≤ A ≤ 90°) is:
If 3 sin2 A + 4 cos2 A - 3 = 0, then the value of cot A (where 0 ≤ A ≤ 90°) is: Correct Answer 0
Given:
3 sin2 A + 4 cos2 A - 3 = 0
Formula used:
sin2 A + cos2 A = 1
Calculation:
3 sin2 A + 4 cos2 A - 3 = 0 ⇒ 3 sin2 A + 3 cos2 A + cos2 A - 3 = 0
⇒ 3 ( sin2 A + cos2 A) + cos2 A - 3 = 0
⇒ 3 + cos2 A - 3 = 0
⇒ cos2 A = 0
⇒ cos A = 0
⇒ A = 90°
⇒ cot A = cot 90° = 0
মোঃ আরিফুল ইসলাম
Feb 20, 2025