highschoolmom2010 2 years ago using Sin, Cos, Tan For parts (a)–(c), find the value of w to the nearest tenth

1. highschoolmom2010

2. ganeshie8

familiar wid SOH-CAH-TOA ?

3. phi

you are zipping along... now learning trig ?

4. phi

5. highschoolmom2010

not really understand but @phi that is in my lessons for geometry

6. ganeshie8

yeah usually they put trig ratios right after similar triangles

7. highschoolmom2010

i can kinda do it not really well yet

8. phi

khan explains it better than trying to learn it from reading explanations here. This site is better for going over your problems

9. highschoolmom2010

ok ok so watch his videos first :D

10. highschoolmom2010

|dw:1375894551709:dw| doesnt really show how to do this @ganeshie8

11. ganeshie8

first go to the 54 degree corner and stare at the triangle from there

12. ganeshie8

|dw:1375895636780:dw|

13. ganeshie8

|dw:1375895683012:dw|

14. ganeshie8

thats opposite side eh ?

15. highschoolmom2010

yes thats the opposite

16. ganeshie8

wat about 17, wat is it

17. phi

Here is khan working this type of problem http://www.khanacademy.org/math/trigonometry/basic-trigonometry/basic_trig_ratios/v/example--trig-to-solve-the-sides-and-angles-of-a-right-triangle

18. phi

the hypotenuse is opposite the 90º angle. 17 in (a) is the hypotenuse

19. highschoolmom2010

idk what i was thinking it is hyp,

20. highschoolmom2010

this is really confusing

21. highschoolmom2010

@phi i think i got it |dw:1375975866022:dw| $\sin 54=\frac{ w }{ 17 }$ $17*\sin 54=\frac{ w }{ 17 }*17$ $17\sin54=W$ $W \approx13.8$

22. phi

yes.

23. highschoolmom2010

ok now can yall check my b and c part when i get the posted

24. ganeshie8

yea sure. remember this - hypotenuse is the longest side. it wont change no matter which corner u go

25. phi

once you get the idea and stay focused (don't make a dumb mistake) and you know how to work a calculator this stuff is not hard.

26. highschoolmom2010

|dw:1375976336846:dw| this one i get mixed up $\tan \frac{ 1.0 }{ W }$ $W* \tan 28=\frac{ 1.0 }{ W }*W$ $W \tan 28=1.0$ im unsure of how to do that

27. phi

remember that tan(28) is some (ugly) number which a calculator will know. divide both sides by tan(28)

28. phi

you get w= 1/tan(28)

29. highschoolmom2010

but when i plug in 1/tan(28) the calculator gave me this -3.55328644813

30. phi

your calculator is in "radian mode" you want to be in degree mode

31. ganeshie8

change the mode to degrees

32. highschoolmom2010

ohh ok

33. highschoolmom2010

1.88

34. highschoolmom2010

so approx 1.9

35. phi

yes

36. highschoolmom2010

horray ok and for the last pne

37. highschoolmom2010

|dw:1375977256082:dw| $\cos(33)=\frac{ w }{ 4.5 }$ $4.5*\cos(33)=\frac{ w }{ 4.5 }*4.5$ $4.5\cos(33)=W$ $W \approx3.8$

38. highschoolmom2010

ty @phi & @ganeshie8 for the help