Question

prove that sec²A - {(sin²A - 2sin⁴A)/(2cos⁴A - cos²A)} = 1​

Answer 1

Answer:

Sin²A + Cos²A = 1

Step-by-step explanation:

= Sec²A - {Sin²A(Cos2A)/Cos²A(Cos2A) }

{ Cos2A = (2Cos²A - 1) = (1 - 2Sin²A) }

= Sec²A - (Sin²A/Cos²A)

= Sec²A - tan²A

= 1 + tan²A - tan²A

= 1

Hence proof