1. Warm up 1. Name the three trig ratios you learned last time. 2.Write the three trig functions as ratios. 3.What is sinA? cosA? tanB? A B C 4 m 3 m 5 m

2. Two more things you should know (that you should have in your notes) Distance formula: D = √(x 2 – x 1 ) 2 + (y 2 – y 1 ) 2 When you add the 2 shortest sides, the sum must be GREATER than the longest side, otherwise they won’t connect and you won’t have a Δ. You should put this info with the acute/obtuse/right inequalities Lengths of the sides of a Δ

3. Using trig ratios in equations Remember back in 1 st grade when you had to solve: 12 = x What did you do? 6 (6) 72 = x Remember back in 3rd grade when x was in the denominator? 12 = 6 What did you do? x (x) 12x = 6 __ 12 x = 1/2

4. x cm 15 cm 34° Ask yourself: In relation to the angle, what pieces do I have? Opposite and hypotenuse Ask yourself: What trig ratio uses Opposite and Hypotenuse? SINE Set up the equation and solve: Sin 34 = x 15 (15) (15)Sin 34 = x 8.39 cm = x

5. x cm 12 cm 53° Ask yourself: In relation to the angle, what pieces do I have? Opposite and adjacent Ask yourself: What trig ratio uses Opposite and adjacent? tangent Set up the equation and solve: Tan 53 = x 12 (12) (12)tan 53 = x 15.92 cm = x

6. x cm 18 cm 68° Ask yourself: In relation to the angle, what pieces do I have? Adjacent and hypotenuse Ask yourself: What trig ratio uses adjacent and hypotnuse? cosine Set up the equation and solve: Cos 68 = 18 x (x) (x)Cos 68 = 18 X = 18 cos 68 _____ cos 68 X = 48.05 cm

7. 42 cm 22 cm θ This time, you’re looking for theta. Ask yourself: In relation to the angle, what pieces do I have? Opposite and hypotenuse Ask yourself: What trig ratio uses opposite and hypotenuse? sine Set up the equation (remember you’re looking for theta): Sin θ = 22 42 Remember to use the inverse function when you find theta THIS IS IMPORTANT!! Sin -1 22 = θ 42 31.59°= θ

8. 17 cm 22 cm θ You’re still looking for theta. Ask yourself: What trig ratio uses the parts I was given? tangent Set it up, solve it, tell me what you get. tan θ = 17 22 THIS IS IMPORTANT!! tan -1 17 = θ 22 37.69°= θ

9. Assignment Trig packet