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January 22, 2017
Posted by **NEED HELP NOWW!!** on Friday, December 2, 2011 at 3:06am.

- TRIGO HELP!!! NEEDED NOW -
**Steve**, Friday, December 2, 2011 at 5:36amyou want a proof?

sec^4 - sec^2 = sec^2(sec^2 - 1)

= sec^2 tan^2

= (tan^2 + 1)(tan^2)

= tan^4 + tan^2