r y x

What do you remember about this triangle? And this one? c b r y x a

r y c x b a

θ And r can be found by… The terminal side of the angle here is r r (1, 2) r θ Starting θ from the positive x-axis is called Standard Position

? θ And r can be found by… The terminal side of the angle here is r r (1, 2) Important Note: the value of r will always be positive r y ? θ x

(1, 2) r θ

So the general formulas look like this: (x, y) r θ

The acute angle made between the terminal side (r) Here θ is the reference angle This is the same θ we saw in the first quadrant reference angle (–1, 2) The acute angle made between the terminal side (r) r and the x-axis θ

Find all of the trig functions of α (–1, 2) r θ Compare these with our QI angle

(1, 2) r θ Same trig values only the cosine and secant are negative in the QII case

Find all of the trig functions of α (–1, 2) r θ

Co-terminal angles Angles that have the same initial and terminal sides (–1, 2) α and β are examples of co-terminal angles. r β Co-terminal angles always differ by multiples of 360° Left off here They also will have the same sine, cosine, tangent, etc.

Find all of the trig functions of α given a terminal side through the point (9, 40) ----- Meeting Notes (9/19/11 09:14) ----- Change symbols; remember that from pc to mac some symbols are blocked

Find all of the trig functions of α given a terminal side through the point (–5, –12) ----- Meeting Notes (9/19/11 09:14) ----- Change symbols; remember that from pc to mac some symbols are blocked

Find all of the trig functions of θ given that …and θ is in Quadrant IV But since we’re in Quadrant IV