Determine the six trigonometric functions of this angle. y=-3x cos  > 0

Question

The square you see is a zero but with a line in the middle symbol

Answer 1

That symbol is a theta, Θ, which is a common variable used to represent an angle in math.

If you graph the linear function y = -3x, you will see that it graphs in QII and in QIV. Since part of the given info tells us cosΘ > 0 , we are looking at the ray in QIV. Draw a perpendicular from this ray back to the + x-axis, and label the acute angle this ray makes with the x-axis Θ_ref . (This is Θ's reference angle.)

Because this ray has a slope of -3, it means that tanΘ = -3 -- notice that the ratio of the leg opposite Θ_ref to the adjacent leg is -3/1. Label the opposite leg -3; label the adjacent 1. Now by Pythag Thm, the hypotenuse is √10.

You can find the remaining 5 trig values for Θ by using SOHCAHTOA trig for Θ_ref.