He angle \theta_1θ
1

theta, start subscript, 1, end subscript is located in Quadrant \text{I}Istart text, I, end text, and \sin(\theta_1)=\dfrac{1}{2}sin(θ
1

)=
2
1

sine, left parenthesis, theta, start subscript, 1, end subscript, right parenthesis, equals, start fraction, 1, divided by, 2, end fraction .
What is the value of \cos(\theta_1)cos(θ
1

)cosine, left parenthesis, theta, start subscript, 1, end subscript, right parenthesis?