1. Find the missing measures. Write all answers in radical form.
Warm – up
Find the missing measures. Write all answers in radical form. x
30°
30 10 z
45 3
60 y
45
60° y

2. Sect 5.4 cont and applications
Agenda for today
Wed
More 5.2 & 5.3 and 5.4
Notes SOHCAHTOA
CW/HW
Thur
Sect 5.4 cont and applications
Fri
Test Unit #4

3. Date: 09/29/09 Questions over hw
Date: 09/29/09 Questions over hw? Standards:MA2G2:a: Discover the relationship of the trigonometric ratios for similar triangles. Students will define and apply sine, cosine, and tangent ratios to right triangles.

4. The Trigonometric Functions we will be looking at
5.2 & 5.3
The Trigonometric Functions we will be looking at
SINE
COSINE
TANGENT

5. The Trigonometric Functions
SINE
COSINE
TANGENT

6. SINE
Pronounced “sign”

7. COSINE
Pronounced “co-sign”

8. Pronounced “tan-gent”

9. Represents an unknown angle
Greek Letter q
Prounounced “theta”
Represents an unknown angle

10. hypotenuse
hypotenuse
opposite
opposite
adjacent
adjacent

11. We need a way to remember all of these ratios…

12. Some
Old
Hippie
Came A
Hoppin’
Through
Our
Old Hippie
Apartment

13. Sin
SOHCAHTOA
Opp
Hyp
Cos
Adj
Hyp
Tan
Opp
Adj
Old Hippie

14. Finding sin, cos, and tan. (Just writing a ratio or decimal.)

15. 10.8 9 A 6 Find the sine, the cosine, and the tangent of angle A.
Give a fraction and decimal answer (round to 4 places).
10.8 9 A 6
Shrink yourself down and stand where the angle is.
Now, figure out your ratios.

16. 24.5 8.2 23.1 Find the sine, the cosine, and the tangent of angle A
Give a fraction and decimal answer (round to 4 decimal places).
8.2 A
23.1
Shrink yourself down and stand where the angle is.
Now, figure out your ratios.

17. Finding a side. (Figuring out which ratio to use and getting to use a trig button.)

18. Ex: 1. Figure out which ratio to use. Find x
Ex: 1 Figure out which ratio to use. Find x. Round to the nearest tenth.
20 m x
Shrink yourself down and stand where the angle is.
tan 20 55 )
Now, figure out which trig ratio you have and set up the problem.

19. Ex: 2 Find the missing side. Round to the nearest tenth.
80 ft x
tan 80  ( 72 ) ) =
Shrink yourself down and stand where the angle is.
Now, figure out which trig ratio you have and set up the problem.

20. Ex: 3 Find the missing side. Round to the nearest tenth.
Shrink yourself down and stand where the angle is.
Now, figure out which trig ratio you have and set up the problem.

21. Ex: 4 Find the missing side. Round to the nearest tenth.
20 ft x

22. Finding an angle. (Figuring out which ratio to use and getting to use the 2nd button and one of the trig buttons.)

23. Ex. 1: Find . Round to four decimal places.
tan
17.2 9 )
17.2 9
Shrink yourself down and stand where the angle is.
Now, figure out which trig ratio you have and set up the problem.
Make sure you are in degree mode (not radians).

24. Ex. 2: Find . Round to three decimal places.7
2nd
cos 7 23 ) 23
Make sure you are in degree mode (not radians).

25. Ex. 3: Find . Round to three decimal places.
200
400
2nd
sin
200
400 )
Make sure you are in degree mode (not radians).

26. When we are trying to find a side we use sin, cos, or tan.
When we are trying to find an angle
we use sin-1, cos-1, or tan-1.

27. Class Work
WS Packet