## anonymous one year ago help.

1. anonymous

@Mizuki

2. Mizuki

hi again

3. Mizuki

wat do u need help with??

4. anonymous

5. anonymous

i understand everything except the red circle part.

6. anonymous

oh yay astrophysics to the rescue <3

7. Astrophysics

It's a property that tells us this $\huge \frac{ a }{ \frac{ b }{ c } } = \frac{ c \times a }{ b }$

8. Astrophysics

So think of it this way, |dw:1436161113139:dw| it's just dividing by fractions really

9. Astrophysics

Remember when you divide fractions, you take the second fraction, flip and multiply

10. Mizuki

that's wat i thought

11. anonymous

12. anonymous

what i'm asking is, shouldn't the entire part be,

13. anonymous

$\frac{ 10 }{ \tan(<BAC) }=\frac{ 10 }{ 9 }$

14. Astrophysics

No because $\tan(< BAC) = \frac{ 10 }{ 9 }$

15. anonymous

why is it like, how it's posted in the example.

16. anonymous

17. Astrophysics

|dw:1436161397822:dw|

18. anonymous

ohhh i get it!

19. anonymous

wait i get it a little!

20. Astrophysics

You're just plugging 10/9 for for that expression, that's all

21. anonymous

|dw:1436161457997:dw|

22. Astrophysics

Yes :)

23. anonymous

what is that 10 then?

24. Mizuki

the 10 on the top of 10/tan(<BAC)

25. anonymous

you understand everything mizuki?

26. Astrophysics

BC = 10, because what you're solving for is AC, |dw:1436161552377:dw|

27. anonymous

can't it be like this though,

28. anonymous

sec

29. Astrophysics

BC = 10

30. Mizuki

yes i do understand everything @Mindblast3r

31. anonymous

|dw:1436161657752:dw|

32. Astrophysics

No, because you're saying that tan(<BAC) = 9 then

33. Astrophysics

But it actually = 10/9

34. Astrophysics

the 10 in the numerator represents BC

35. anonymous

ohhh and 10/9 is a ratio right?

36. Astrophysics

Yes, that the tan ratio

37. anonymous

and you use that ratio to solve for the missing side (adjacent).

38. anonymous

correct?

39. Astrophysics

Yes, because they told you that tan(<BAC) = 10/9 (for the angle of triangle)

40. Mizuki

|dw:1436161889108:dw|

41. anonymous

ohhh!!

42. Astrophysics

But what you're looking for is the side AC

43. Mizuki

get it now??

44. anonymous

|dw:1436162002962:dw|

45. Astrophysics

Awesome :)

46. Mizuki

great!! :)