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Find the value of $ cos( heta) $ using the unit circle when $ heta = frac{5pi}{4} $

Answer 1

Abigail Nelson

Chloe Evans

To find the value of $ \cos(\theta) $ using the unit circle when $ \theta = \frac{5\pi}{4} $, we first locate this angle on the unit circle.

The angle $ \theta = \frac{5\pi}{4} $ lies in the third quadrant.

We know that $ \theta = \frac{5\pi}{4} $ is equivalent to $ 225^{\circ} $.

In the third quadrant, both sine and cosine are negative.

On the unit circle, the coordinates for $ 225^{\circ} $ are $ (-\frac{\sqrt{2}}{2}, -\frac{\sqrt{2}}{2}) $.

Therefore, $ \cos(\frac{5\pi}{4}) = -\frac{\sqrt{2}}{2} $.

Answer 2

Alex Thompson

Benjamin Clark

To find the value of $ cos( heta) $ when $ heta = frac{5pi}{4} $ using the unit circle, note that this angle corresponds to $ 225^{circ} $ and lies in the third quadrant.

The coordinates at $ 225^{circ} $ are $ (-frac{sqrt{2}}{2}, -frac{sqrt{2}}{2}) $.

Therefore, $ cos(frac{5pi}{4}) = -frac{sqrt{2}}{2} $.

Answer 3

Amelia Mitchell

Isabella Walker

The value of $ cos(frac{5pi}{4}) $ using the unit circle is $ -frac{sqrt{2}}{2} $.