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Math Help - Solving Trig Idenities PLZ NEED HELP

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    Solving Trig Idenities PLZ NEED HELP

    Hi there I need help with this question! It says to factor out the left side of the equation but I don't see how it works. Can someone please leave me a step by step guide? Thank you!!!!

    Question:

    cos4x + 2cos2xsin2x + sin4x = 1
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    Quote Originally Posted by Sarah32 View Post
    Hi there I need help with this question! It says to factor out the left side of the equation but I don't see how it works. Can someone please leave me a step by step guide? Thank you!!!!

    Question:

    cos4x + 2cos2xsin2x + sin4x = 1
    I presume this is
    cos^4(x) + 2cos^2(x)sin^2(x) + sin^4(x) = 1

    Note that the LHS is a perfect square. If your teacher gave you the factoring problem
    x^4 + 2x^2 y^2 + y^4
    you would probably see more easily that this is
    = (x^2 + y^2)^2

    So your equation becomes
    (cos^2(x) + sin^2(x))^2 = 1

    -Dan
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