Help with proofs!!! Please!!!

[mmmPi]

For whatever reason proofs are just not clicking with me... can someone please help me solve 2 of them?

The instructions state "Prove the identity" and give me these two problems to "prove". I'm too take the left side and manipulate it to prove that it equals the right.

cosx(cotx)+sinx=cscx

...and...

cosx+sinx(tanx)=secx

I just have trouble figuring out where to begin...
Thank you so much!

 

[stapel]

What is the theorem that you are trying to prove? (All I see in your post is two equations, no question or "prove" statement, is why I ask.)

Please reply with the full and exact text of the exercise, the complete instructions, a detailed description of any required graphic, and a clear listing of everything you have tried thus far.

Thank you.

Eliz.

 

[Sid]

Don't quote me, but I just did this stuff last week

cosx(cotx)+sinx=cscx

cosx(cosx/sinx) = cos^2/sin

cos^2/sin + sin = cos^2/sin + sin^2/sin

cos^2+ sin^2 = 1

so that equals 1/sin which equals csc


...and...

cosx+sinx(tanx)=secx

cos = cos/1
sin = sin/1
tan = sin/cos

so:

sin(sin/cos) = sin^2/cos

cos/1 + sin^2/cos (find least common denominator)

cos^2/cos + sin^2/cos = 1/cos (since cos^2+sin^2 = 1)

Hope this helps, but don't quote me!

-Sid