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Find the image of the unit circle under the transformation $ f(z)=z^2 $

Answer 1

Abigail Nelson

Emily Hall

The unit circle in the complex plane is given by $ |z| = 1 $, meaning any point $ z $ on the unit circle can be written as $ z = e^{i\theta} $ for some real number $ \theta $.

Under the transformation $ f(z) = z^2 $, the image of $ z $ is:

$ f(z) = (e^{i\theta})^2 = e^{i(2\theta)} $

Since $ e^{i(2\theta)} $ is still a point on the unit circle, the image of the unit circle under $ f(z) = z^2 $ is the unit circle itself.

Answer 2

Alex Thompson

Thomas Walker

The unit circle is represented by $ |z| = 1 $, so any point $ z $ can be written as $ z = e^{i heta} $.

Under $ f(z) = z^2 $, we have:

$ f(z) = (e^{i heta})^2 = e^{i(2 heta)} $

The image remains on the unit circle, meaning the unit circle maps to itself under the transformation.

Answer 3

Amelia Mitchell

Emma Johnson

The unit circle $ |z| = 1 $ transforms under $ f(z) = z^2 $ to:

$ f(z) = e^{i(2 heta)} $

Thus, the image is the unit circle.