The value of (tan2 A + cot2 A - 2) - sec2 A cosec2 A is :
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. -4
⇒ (tan2 A + cot2 A - 2) - sec2 A cosec2 A
⇒ (sin2A/cos2A + cos2A/sin2A - 2) - 1/sin2ACos2A
⇒ ((sin4A + cos4A - 2sin2Acos2A) /sin2Acos2A) - 1/sin2ACos2A
⇒ ((sin4A + cos4A - 2sin2Acos2A + 2sin2Acos2A - 2sin2Acos2A) /sin2Acos2A) - 1/sin2ACos2A
⇒ ((sin4A + cos4A + 2sin2Acos2A - 4sin2Acos2A ) /sin2Acos2A) - 1/sin2ACos2A
⇒(1 - 4sin2Acos2A - 1)/sin2ACos2A
⇒ -4.