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Math Help - simplify trig expression

  1. #1
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    simplify trig expression

    Using the definations of sec, cosec, cot and tan simplify the following expression;

     sec^2x cos^5x + cotx \ cosecx \ sin^4x
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  2. #2
    Super Member malaygoel's Avatar
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    we have
    secx=\frac{1}{cosx}

    cotx=\frac{cosx}{sinx}

    cosecx=\frac{1}{sinx}


    Quote Originally Posted by Tweety View Post

     sec^2x cos^5x + cotx \ cosecx \ sin^4x
    =(\frac{1}{cosx})^2.\ cos^5x + \frac{cosx}{sinx} .\ \frac{1}{sinx}. \ sin^4x

    =cos^3x+cosx\sin^2x

    =cosx(cos^2x+sin^2x)

    =cosx.............ANSWER

    since cos^2x+sin^2x=1
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  3. #3
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    Thanks,

    thats also the same answer I got but my book says the correct answer is cosx

    could the book be wrong?
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  4. #4
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    Quote Originally Posted by Tweety View Post
    Thanks,

    thats also the same answer I got but my book says the correct answer is cosx

    could the book be wrong?
    you need to take another look at malaygoel's solution.
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  5. #5
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    Quote Originally Posted by skeeter View Post
    you need to take another look at malaygoel's solution.
    ops sorry just realised ,

    thanks
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