?

Trigonometry

Free Version

Upgrade subject to access all content

Easy

Double Cosine from Sine

TRIG-YEYBKK

If $\sin { \theta } =\cfrac { 15 }{ 17 }$ and ${ \theta }$ lies in Quadrant $I$, find $\cos { 2\theta }$.

A

$-\cfrac{161}{289}$

B

$\cfrac{8}{17}$

C

$\cfrac { 16 } { 17 }$

D

$-\cfrac { 225 } { 289 }$

E

$\cfrac { 161 } { 289 }$