HELP NEEDED with Trig Identities!?

Question

Really don't know where to start with this one so any help would be great. I'm trying to simplify the equation:

Cos^2Ǿ + Sec^2Ǿ + Sin^2Ǿ - 2

10 point for the best answer...

Answer 1

Identities you need:

Cos^2Ǿ + Sin^2Ǿ = 1

Sec^2Ǿ = Tan^2Ǿ + 1

Tan^2Ǿ = Sec^2Ǿ - 1

Cos^2Ǿ + Sec^2Ǿ + Sin^2Ǿ - 2

Cos^2Ǿ + Sin^2Ǿ + Sec^2Ǿ - 2

Sec^2Ǿ - 2 + 1

Sec^2Ǿ - 1

Tan^2Ǿ       ANSWER

Answer 2

here...

remember

the 1st rule.

  cos^2 Ǿ + sin^2 Ǿ = 1

then

   cos^2 Ǿ + sin^2 Ǿ + sec^2 Ǿ  -  2 =

                1             + sec^2 Ǿ  -  2 =

                                  sec^2 Ǿ  -  1        = tan^2 Ǿ.

thx

Answer 3

cos^2 a + sin^2 a + sec^2 a - 2 = sec^2 a - 1 = tan^2 a

Answer 4

Cos^2Ǿ + Sec^2Ǿ + Sin^2Ǿ - 2

Cos^2Ǿ +1/Cos^2Ǿ +Sin^2Ǿ -2

but Sin^2Ǿ +Cos^2Ǿ =1

so u have

1-2+1/Cos^2Ǿ  = 1/Cos^2Ǿ -1

                       =Sec^2Ǿ -1

                        =tan^2Ǿ