Given each point P(x, y), lying on the terminal arm of angle Θ:

i) state the value of Θ, using both a counterclockwise and a clockwise rotation.

ii) determine the primary trigonometric ratios

10c) P (-1, 0)

So, this is what I did:

x = -1, y = 0, r = 1

sinΘ = 0/1

sinΘ=0

cosΘ = -1/1

cosΘ = -1

tanΘ = 0/1

tanΘ = 0

And then to determine the counterclockwise and clockwise ratios (this is the part I got wrong), I did...

cosΘ = -1

Θ = 180

180+180 = 360

180-180 = 0

However, this is wrong according to the textbook. It says the answer is: 180 and -180 degrees. Can someone explain how they got that? Thanks!