I have no idea how to solve this!
It's about Verifying trigonometric identities.
Here's the problem:

1 divided by 1+tanx = cotx divided by 1+cotx

Wouldn't it be easier to write:

1/(1+tan(x))=cot(x)/(1+cot(x))

Or, in LaTeX:



To see the code I used to make it display that way, click on 'quote' at the lower right corner of this post.

Just cross multiply:



Now, can you see it? What does

equal?

THank you !

So for another one, I have
4tanxcos²x-2tanx/1-tan²x=2tanx/1-tan²x.
So far, I have simplified it to 2tanxcos²x/1-tan²x.
Could I set up a proportion setting my identities equal to each other?

Are you allowed to cross multiply in proving identities :confused:

My method would be to divide both sides by tan, or cot, depending on where you are starting from.






This is using the fact that

~~~~~~~~~~~~~~~~


I don't think this is a true identity, because:

Multiply both sides by 1 - tan^2x gives a new identity:



Adding 2 tan x to give this new identity:



Factor 4tan x on the left:



Simplifies to



And as required for the identity to be true.

Either that, or you did a typing mistake, the identity should be instead: