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Putting complex numbers into exponential form.?

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Put the complex number 2 + 3i into its exponential form and hence find the three

complex roots of

z^3- 2 - 3i = 0

Determine the Cartesian form of these three roots.

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  2. it would help by studying your math book

    i will give you a link on euler's formula, this will help you understand

    http://en.wikipedia.org/wiki/Euler%27s_f...

  3. 2 + 3 i = √13 /_ Ó¨  where Ó¨ = tan ^(-1) (3/2) = 0.625

    Z³ = √13 [cos (0.625 + 2kπ) + i sin (0.625 + 2kπ ) ]

    Z is , for k = 0 , 1 , 2 , given by :-

    13^(1/6) [cos {(0.625 + 2kπ)/3}+ i sin {(0.625 + 2kπ)/3]

    z1 = 13^(1/6) ( cos 0.208 + i sin 0.208 )

    z2 = 13^(1/6) ( cos 2.3+ i sin 2.3)

    Z3 = 13^(1/6) ( cos 4.4+ i sin 4.4)

    z1 = 13^(1/6) ( 0.98 + i 0.21 )

    z2 = 13^(1/6) ( - 0.67 + i 0.75)

    Z3 = 13^(1/6) (- 0.31- i 0.95)

  4. 2+3i = (rt13)[ cosT +isinT] where cosT = 2/rt13 and sinT= 3/rt13

    2+3i = (rt13) e^(iT) etc.

    So z = [(rt13) e^(iT)]^(1/3)

            = (6th root of 13) {Cos[(2pik/3)+(T/3)] +isin[(2pi/3)+(T/3)]} for k = 0,1 and 2.

  5. Let x=2 and y=3

    r=sqrt[4+9]=sqrt[13]

    theta=tan[3/2]

    The exponential form of 2+3i is sqrt[13]*exp[tan(3/2)]

    Now, z^3=2+3i=sqrt[13]*exp[tan(3/2)]=

    sqrt[13]*exp[2npi+tan(3/2)]

    ==>z=sixth root[13]*exp[tan(3/2)] or

    sixthroot[13]*exp[2pi+tan(3/2)]

    or sixthroot[13]*exp[4pi+tan(3/2)]

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