The angle \theta_1θ 1 theta, start subscript, 1, end subscript is located in Quadrant \text{IV}IVstart text, I, V, end text, and \sin(\theta_1)=-\dfrac{13}{85}sin(θ 1 )=− 85 13 sine, left parenthesis, theta, start subscript, 1, end subscript, right parenthesis, equals, minus, start fraction, 13, divided by, 85, end fraction. What is the value of \cos(\theta_1)cos(θ 1 )cosine, left parenthesis, theta, start subscript, 1, end subscript, right parenthesis? Express your answer exactly