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Course: Get ready for Precalculus?>?Unit 4

Lesson 3: The Pythagorean identity

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Use the Pythagorean identity

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The angle

θ_{1}

is located in Quadrant

IV

, and

\sin ? (θ_{1}) = ? \frac{13}{85}

.

What is the value of $\cos ? (θ_{1})$ ??
Express your answer exactly.

\cos ? (θ_{1}) =

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Using the Pythagorean trig identity