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Math Help - Prove that z^(k+1) is true for n=k+1

  1. #1
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    Prove that z^(k+1) is true for n=k+1

    I'm having some problem recalling the trig identity.

    I've work up till this part:

    r^k . r^1 [Cos(k.theta)Cos(theta)-Sin(K.theta)Sin(theta)+i(Cos(theta)Sin(K.theta)+Co s(K.theta)Sin(theta)]

    I need to reduce the above to its relevant trig identity to yield: r^(K+1) [Cos(K+1)theta + iSin(K+1)theta]


    Solved: Thread to be delete
    Last edited by Darrylcwc; October 25th 2013 at 06:46 AM.
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  2. #2
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    Re: Prove that z^(k+1) is true for n=k+1

    Hey Darrykwc
    I believe you are trying to prove De Moivre's Theorem.
    Find the proof here
    De Moivre's formula - Wikipedia, the free encyclopedia
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  3. #3
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    Re: Prove that z^(k+1) is true for n=k+1

    Quote Originally Posted by Darrylcwc View Post
    I'm having some problem recalling the trig identity.

    I've work up till this part:

    r^k . r^1 [Cos(k.theta)Cos(theta)-Sin(K.theta)Sin(theta)+i(Cos(theta)Sin(K.theta)+Co s(K.theta)Sin(theta)]

    I need to reduce the above to its relevant trig identity to yield: r^(K+1) [Cos(K+1)theta + iSin(K+1)theta]


    Solved: Thread to be delete
    No, the thread should NOT be deleted. Instead you should post your solution so that others who might be having a similar trouble in future might be able to refer to it.
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