Question 6933b3d9

Geometry and Trigonometry - Right triangles and trigonometry

The figure presents right triangle R S T such that side R T is horizontal, vertex T is to the right of vertex R, and vertex S is above R T. Side R S is labeled 12. Side S T is labeled 5. Angle S is a right angle

In triangle RST above, point W (not shown) lies on $line segment R T$ . What is the value of $cosine of angle R S W, minus sine of angle W S T$ ?