Halloween Unit Circle Warm-up! Your right arm is the initial side and your left arm is the terminal side. Ready? Let’s go! 360° ° -2π 2 π -270° π - π And by the way, we have a no- calculator quiz on Thursday. =)

Check HW sinθ = 3/5 17.,23. 30°, cosθ = 4/5 tanθ = 3/418., °, cscθ = 5/3 secθ = 5/ °, °, cotθ = 4/5 3. sinθ = 9/ °, °, cosθ = 40/41 tanθ = 5/ °, cscθ = 41/9 secθ = 41/ °, cotθ = 12/5

Reference Angles A reference angle is the acute angle formed by the terminal side of θ and the x-axis. For example, the reference angle of is. 225°45°

Sketch the angle, then find the reference angles for the following: 1.240° 2. 3.

How are the references angles helpful? If you can remember the trig identities for,, and, then you know the identities for every angle in the unit circle. Try We know it’s going to at the point, but think of which quadrant it is in… Quadrant II, so it must be.

Complete the trig function chart without referring to a calculator or unit circle, find the values of the trig identity. Remember (x-cos, y-sin) and the tangent is. I will test when you’re done.

Now try going the other way around… If the value of the trig function is given, can you find the angle? cosθ = 0

Trig Identity Bingo! HW 4.4: Pg. 319 #37-42, 51-54, 81, 82, 86

Thinking Outside the Unit Circle… Evaluating Trig Functions Find the sine, cosine, and tangent of θ, given a a point on the terminal side. Make a right triangle Find the length of each side. Use the (-3, 4) θ 3 4