SOLUTION: I am trying to solve: sec^2 77 degrees-tan^2 77 degrees. I know that I need to use the fundamental trig identities to arrive at the solution, but I am having trouble applying one.

Algebra ->  Trigonometry-basics -> SOLUTION: I am trying to solve: sec^2 77 degrees-tan^2 77 degrees. I know that I need to use the fundamental trig identities to arrive at the solution, but I am having trouble applying one.       Log On


   

Question 349045: I am trying to solve: sec^2 77 degrees-tan^2 77 degrees. I know that I need to use the fundamental trig identities to arrive at the solution, but I am having trouble applying one.
Thank you!
Answer by Jk22(389) About Me  (Show Source):
You can put this solution on YOUR website!
sec(77)^2-tan(77)^2=1/cos(77)^2-sin(77)^2/cos(77)^2 | def. of sec and tan

=(1-sin(77)^2)/cos(77)^2

=cos(77)^2/cos(77)^2 | cos^2+sin^1=1 trig. identity

=1.