Thread: Verifying Trig Identities?

Hello there.

I am having some trouble in studying verifying trig identities for my Math final.


____1____ + _____1____ = 2Sec^2x
1-Sinx 1+Sinx


It's 1 over 1-Sinx plus 1 over 1 plus Sinx, equals 2 Sec squared x. I can't figure this one out. I think you have to get a common denominator, but I'm not sure, what to do after that.

1-Sinx
_________ = Sec^2x - 2secxtanx+tan^2x

1+Sinx

For this one, you work almost exclusively on the right side, no? I got (Secx-tanx)(Secx-tanx).

From there don't you use reciprocal identities? After that, I am stuck.

Any help would be appreciated. Also, since I am positive these will be on my final, can anyone give me general help/tips on solving these? A link to a good site would be very helpful. Thanks in advance.

Originally Posted by Quasimoto

Hello there.

I am having some trouble in studying verifying trig identities for my Math final.


____1____ + _____1____ = 2Sec^2x
1-Sinx 1+Sinx


It's 1 over 1-Sinx plus 1 over 1 plus Sinx, equals 2 Sec squared x. I can't figure this one out. I think you have to get a common denominator, but I'm not sure, what to do after that.

1-Sinx
_________ = Sec^2x - 2secxtanx+tan^2x

1+Sinx

For this one, you work almost exclusively on the right side, no? I got (Secx-tanx)(Secx-tanx).

From there don't you use reciprocal identities? After that, I am stuck.

Any help would be appreciated. Also, since I am positive these will be on my final, can anyone give me general help/tips on solving these? A link to a good site would be very helpful. Thanks in advance.

Dear Quasimoto,

For the first one, get the common denominator as suggested. Then you should know that,



The second part could also be solved using the above identity.

Hope you can continue.