SOLUTION: Find the cosine (cos) of the angle in standard position determined by the point (-7, -3)

The point is in QIII, where cosine is NEGATIVE.



cos(a) is the ratio of the adjacent leg (which is -7 in this case) to the hypotenuse length;

    the sign of the ratio should be selected as a " - " (minus).



The hypotenuse length is   =  = .



Hence, the answer is  cos(a) = - .