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Find the cosine of a point on the unit circle in the complex plane

Answer 1

Abigail Nelson

Joseph Robinson

Given a point on the unit circle in the complex plane, represented by the complex number $z = e^{i\theta}$, determine the value of $\cos(\theta)$.

Since $z = e^{i\theta}$, we know that:

$z = \cos(\theta) + i\sin(\theta)$

Thus, the real part of $z$ is $\cos(\theta)$. Therefore, the value of $\cos(\theta)$ is simply the real part of $z$.

Hence, if $z = e^{i\theta} = \cos(\theta) + i\sin(\theta)$, then $\cos(\theta) = \text{Re}(z)$.

Answer 2

Alex Thompson

Maria Rodriguez

Given the point $z$ on the unit circle in the complex plane, where $z = e^{i heta}$, we are asked to find $cos( heta)$.

We know Euler’s formula states:

$e^{i heta} = cos( heta) + isin( heta)$

Therefore, the real part of $z$ (which is $e^{i heta}$) is $cos( heta)$. So, the value of $cos( heta)$ is the real part of $z$.

Thus, if $z = e^{i heta}$, then $cos( heta) = ext{Re}(z)$.

Answer 3

Amelia Mitchell

Abigail Nelson

Given $z = e^{i heta}$ on the unit circle, find $cos( heta)$.

From Euler’s formula:

$e^{i heta} = cos( heta) + isin( heta)$

The real part of $z$ is $cos( heta)$.