The equation, with a restriction on x, is the terminal side of an angle theta in standard position. y= -2x quadrant iv. give the exact values of the six trigonometric functions of theta. select the correct choice below and fill in any answer boxes within your choice.

In Q4, the terminal ray of our reference angle is the hypotenuse of the right triangle created by connecting the end of the terminal ray to the positive x-axis.  Theta is the angle between these 2.  In the equation, in the simplest form, if we sub in a 1 for x, then y = -2.  That means the distance along the x axis (the base of the right triangle) is 1, and the height of the triangle is -2.  We need now to find the measure of the hypotenuse using Pythagorean's Theorem.    and    so  .  The sin of theta is the ratio of the side opposite over the hypotenuse, so ,  and .    and .    so  .  There you go!