Ask Experts Questions for FREE Help !
    musicrulez's Avatar
    musicrulez Posts: 3, Reputation: 1
    New Member

    Jan 5, 2011, 11:43 PM
    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
    galactus's Avatar
    galactus Posts: 2,271, Reputation: 282
    Ultra Member

    Jan 6, 2011, 05:47 AM

    Wouldn't it be easier to write:


    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

    musicrulez's Avatar
    musicrulez Posts: 3, Reputation: 1
    New Member

    Jan 11, 2011, 05:31 PM
    Comment on galactus's post
    THank you !
    musicrulez's Avatar
    musicrulez Posts: 3, Reputation: 1
    New Member

    Jan 11, 2011, 05:36 PM
    Comment on galactus's post
    So for another one, I have
    So far, I have simplified it to 2tanxcos²x/1-tan²x.
    Could I set up a proportion setting my identities equal to each other?
    Unknown008's Avatar
    Unknown008 Posts: 8,076, Reputation: 723
    Uber Member

    Jan 11, 2011, 10:24 PM

    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:

Not your question? Ask your question View similar questions


Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.

Check out some similar questions!

Proofing Pre Calculus Identities [ 3 Answers ]

prove the following identities? a.) (1 - cosX)(cscX + cotX)=sinX

Precalculus Word [ 3 Answers ]

Here's the problem: The growth rate y (in pounds per month) of infants is related to their present weight x (in pounds) by the formula y=cx(21-x) for some constant c>0. At what weight is the rate of growth a maximum. It says I need to use the -b/2a formula, but I'm not sure how to use that...

Precalculus - Identities [ 1 Answers ]

I'm stuck on a problem, and I want to figure it out so that I will know it later if it might appear on a test or something. cot2A = 1/2(cotA-tanA) Thanks!

View more questions Search