Question

Prove that : Cosec2A+Cosec4A+Cosec8A=CotA-Cot8A

Answer 1

hey mate.
here's the proof

Answer 2

 Type your question



Jassi asked in Math

prove cosec2A+ cot4A = cotA - cosec4A

Share 

 4

 Follow2



Ashutosh Verma answered this
in Math, Class

Answer :

We have : Cosec 2 A + Cot 4 A = Cosec 4 A - Cot 2 A

Taking LHS  :

⇒Cosec 2 A + Cot 4 A

⇒Cosec 2 A + ( Cot 2 A )2 

⇒Cosec 2 A + ( Cosec 2 A - 1 )2                                         (  we know : 1 + Cot 2 θ =  Cosec 2 θ )

⇒Cosec 2 A +  Cosec 4 A  + 1  - 2 Cosec 2 A

⇒ Cosec 4 A  + 1  - Cosec 2 A

⇒ Cosec 4 A  + 1  - ( 1 + Cot 2 A)

⇒ Cosec 4 A  + 1  -  1 - Cot 2 A

⇒ Cosec 4 A  - Cot 2 A

LHS  =  RHS                                          ( Hence proved )