Question

Tan^4 a+tan^2 a =1 then prove that cos^4 a+cos^2 a=1

Answer 1

Answer:

Step-by-step explanation:

Tan⁴A + Tan²A = 1

=> Tan²A(Tan²A+ 1) = 1

=> Tan²A * Sec²A = 1

=> Sin²A = Cos⁴A.

Now Cos⁴A + Cos²A

 => Sin²A + Cos²A

 => 1

= R.H.S

Hence Proved.