Confused by a Trig problem ???

[slimjimjo]

I dont understand why Sin B= 12(sin A/a) is done on calculator using sin inverse function but a problem like........ c= 22/sin 42)/(sin116.59) is not?

Can someone give me the breakdown on this?


Thanks in advance so much!

 

[mmm4444bot]

Sin B= 12(sin A/a)

c= 22/sin 42)/(sin116.59)

Do you know how to use function notation? Both of the lines above are missing grouping symbols around the input to the sine function.

In other words, are you dividing sin(A) by a or is it sin(A/a) ?

Is c equal to 22/sin(42)/sin(116.59) ?

Please be clear.

 

[slimjimjo]

reply

sorry im so new to trig

well the problem is written like this....


sin B/b = sin A/a step 2: Sin B = b(sin A/a) step 3: plug in given : sin B= 12(sin 42/22)

Answer B = 21.41


To solve with calculator I had to use Sin -1 (Inverse that is)

anyway, again I am new to trig and making an A in Statistics and a D in Trig lol Trig is soooooo hard to me.

Thanks mmm4444bot

Thanks

 

[pappus]

sorry im so new to trig

well the problem is written like this....


sin B/b = sin A/a step 2: Sin B = b(sin A/a) step 3: plug in given : sin B= 12(sin 42/22)

Answer B = 21.41


To solve with calculator I had to use Sin -1 (Inverse that is)

anyway, again I am new to trig and making an A in Statistics and a D in Trig lol Trig is soooooo hard to me.

Thanks mmm4444bot

Thanks

1. I assume that you applied the Sine rule. (It would has been very helpful for us if you had mentioned this.)

2. I assume that the arguments of the trigonometric functions are in degrees. As you've written your equations the arguments of the sine function would be in radians.

3. Learn some LaTeX (or use grouping symbols) to write the mathematical expressions unambiguously:

$\displaystyle \displaystyle{\frac{\sin(A)}{a} = \frac{\sin(b)}{b}~\implies~\sin(B)=b \cdot \frac{\sin(A)}{a}}$

4. With your values:

$\displaystyle \displaystyle{\sin(B)=12 \cdot \frac{\sin(42^\circ)}{22}~\implies~B \approx 21.41^\circ}$

 

[mmm4444bot]

the problem is written like this


sin A/a

Please ask your instructor to clarify whether "sin A/a" means sin(A)/a or sin(A/a).

Got it?

PS: Function notation is a prerequisite for trigonometry.

 

[slimjimjo]

reply

do I have LaTeX on my computer or is this a program I need to install?

Also, what are some suggestions to speed up my learning and retaining of trig material?

my instructor has a heavy accent and is hard to follow at my college. I therefore go home and think I can just spend more time with the Text book but it has been very hard.


Thanks!:evil:

 

[mmm4444bot]

what are some suggestions to speed up my learning and retaining of trig material?

Pay attention.

(If you cannot understand the professor, speak up and ask for clarification.)