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    • Thread Starter

    EDIT: I figured it out, answer is 5root2 as it referring to the argand diagram, I got the answer via Pythagoras if anyone else finds this useful...

    Ok, so it was my understanding that when using modulus you simply state the size of the number so |-5| = 5 and |4i| = 4 but I don't understand this question, I keep getting 0. Thanks in advance for any help. (question b)
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    Imagine the number a + bi as a units on the real (horizontal) axis and b units on the imaginary (vertical axis), just like plotting a vector <a, b>. Using Pythagoras' theorem, you can get the length of the vector, similarly the modulus of a number a + bi is defined as \sqrt{a^2 + b^2}. So |5-5i| = \sqrt{5^2 + 5^2} = \sqrt{50} = 5\sqrt{2}.

    (Original post by Halmos)
    that was what he did


    we still do not give full solutions
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