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Math Help - Quick and easy question trig identities

  1. #1
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    Quick and easy question trig identities

    Hey, I am just starting my trig identities unit and I have a question I'm stuck on.. it's probably very easy, so bear with me and don't make fun of me ^^

    (sec˛x + csc ˛x) - (tan˛x - cot˛x)
    So I have ( 1/cos˛x+ 1/sin˛x) - (sin˛x/cos˛x+ cos˛x/sin˛x)...
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  2. #2
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by Slipery View Post
    Hey, I am just starting my trig identities unit and I have a question I'm stuck on.. it's probably very easy, so bear with me and don't make fun of me ^^

    (sec˛x + csc ˛x) - (tan˛x - cot˛x)
    So I have ( 1/cos˛x+ 1/sin˛x) - (sin˛x/cos˛x+ cos˛x/sin˛x)...
    i suppose you want to simplify here? that's good. now just combined the fractions in each set of brackets. then combine the two resulting fractions
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  3. #3
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    Yes, just simplify.

    For the first bracket, (1/cos˛x + 1/sin˛x)
    can I change the cos˛x and sin˛x to 1 and have it as 1+1= 2?
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  4. #4
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    Hello, Slipery!

    Your work is correct, but are you aware of these identities?

    . . . \begin{array}{ccc}\sec^2\!x \:=\:\tan^2\!x + 1 & \Rightarrow & \sec^2\!x - \tan^2\!x \:=\:1 \\<br />
\csc^2\!x \:=\:\cot^2\!x + 1 & \Rightarrow & \csc^2\!x - \cot^2\!x \:=\:1\end{array}


    Simplify: . (\sec^2\!x + \csc^2\!x) - (\tan^2\!x + \cot^2\!x)

    We have: . (\sec^2\!x - \tan^2\!x) + (\csc^2\!x - \cot^2\!x) \;\;=\;\;1 + 1 \;\;=\;\;2

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  5. #5
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    Ahhh, that is very helpful. thank you both soroban and jhevon.
    I honestly think my brain has issues with this type of work, it just wont' draw the connections.
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