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I need help with this practice problem solving It is trigonometry The instructions are at the bottom

I need help with this practice problem solving It is trigonometry The instructions-example-1
User Enlyte
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1 Answer

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Being z a complex number:


z=x+iy

The modulus of z is:


\lvert z\rvert=\sqrt[]{x^2+y^2}

For the given complex number:


\begin{gathered} z=6-3i \\ \\ \lvert z\rvert=\sqrt[]{6^2+(-3)^2} \\ \lvert z\rvert=\sqrt[]{36+9} \\ \lvert z\rvert=\sqrt[]{45} \\ \\ \text{Simplify:} \\ \lvert z\rvert=\sqrt[]{5\cdot3^2} \\ \lvert z\rvert=3\sqrt[]{5} \end{gathered}Then, the modulus of the given complex number is 3√5
User Mirjam
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