Question

sec⁴ A - sec² A = ___________​

Answer 1

https://qiita.com/nemod/items/5066c64f443823855bed

https://qiita.com/wagid/items/249471f71071f97b1680

https://qiita.com/golisib/items/f7b88bd49cc5a4426819

https://qiita.com/bewen/items/1645905b654d6c54df60

https://qiita.com/ravoro/items/21ae8d080721b06ea727

https://qiita.com/mocid/items/57c05b13b8ab3d39f195

https://qiita.com/yiwewek/items/fed5bca6959e2a12fdc4

https://qiita.com/yobah/items/0ca8fd9ff1c673f966d2

https://qiita.com/naxawe/items/4646a7563213703d41ca

https://qiita.com/payab7/items/952e1bcee0d542061154

https://qiita.com/xedahow/items/6fe9603a963bdcab785d

https://qiita.com/jedije/items/8c08e947f67f7fed8d07

Answer 2

Answer:

⇒sec⁴ A - sec² A

=sec²A(sec²A-1)  ;     sec²A-1=tan²A

=sec²A.(tan²A) ;            sec²A=tan²A+1

=(tan²A+1)(tan²A)

=tan⁴A+tan²A