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{10}{13}sin(θ 1 ​ )=− 13 10 ​ sine, left parenthesis, theta, start subscript, 1, end subscript, right parenthesis, equals, minus, start fraction, 10, divided by, 13, end fraction . What is the value of \cos(\theta_1)cos(θ 1 ​ )cosine, left parenthesis, theta, start subscript, 1, end subscript, right parenthesis?

Luke started a weight-loss program. the first week, he lost x pounds. the second week, he lost pounds less than times the pounds he lost the first week. the third week, he lost 1 pound more than of the pounds he lost the first week. liam started a weight-loss program when luke did. the first week, he lost 1 pound less than times the pounds luke lost the first week. the second week, he lost 4 pounds less than times the pounds luke lost the first week. the third week, he lost pound more than times the pounds luke lost the first week.