I need help with trigonometry

[Littledude]

It's just not rendering in my head at all. I think I must be handicapped or something because it's a simple concept that I just don't get.  We're learning Law of Sines and Cosines right now. FOr law of sine I understand how to set it up but once I get to the

My question is hwo do I get from this :      to this:  

Oh and I'm trying to use this site to help me: http://www.trigonometry-help.net

[Ad Bot]

[dkamm65]

mai brane am payned frum dis topek

[Muzzles56]

Im confuzzled

[SupremeCommander]

2/(sin45) = 1/(sinA)
(sinA)(2/(sin45) = 1/1 = 1
(sinA) = (1/(2/sin45))
sinA = ((1/1)/(2/sin45))
therefore: SinA = ((sin45)/2)
Since sin45 = (square root 2)/2
SinA = ((Square root 2)/2 divided by (2/1).) = (sqroot 2)/4

Hope that helps.

Be aware that 1 = (1/1), and that you can shift things to either side of the equals sign, by changing the sign with the side.
You know that sin 45 = (root 2)/2 from your unit circle. If you don't know what this is, life is a little harder.

[SupremeCommander]

That is officially my proof that I am older than 10, at WhoDa.

[Muzzles56]

That is officially my proof that I am older than 10, at WhoDa.

Obviously copypasta

[SupremeCommander]

Obviously copypasta

Shoo, you.
It's simple.

[Muzzles56]

Shoo, you.
It's simple.

Nu its copypasta
Mmmmmm pasta

[Littledude]

Sadly even if I do get it before I have to go to school I won't have time to finish my homework. Luckily looking at the weather forecast for my area it's possible that I would have an early dismissal. As snow is supposed to start around 11:00 which is before my Pre-Calculus class.

[Game master pro]

2/(sin45) = 1/(sinA)
(sinA)(2/(sin45) = 1/1 = 1
(sinA) = (1/(2/sin45))
sinA = ((1/1)/(2/sin45))
therefore: SinA = ((sin45)/2)
Since sin45 = (square root 2)/2
SinA = ((Square root 2)/2 divided by (2/1).) = (sqroot 2)/4

Hope that helps.

Be aware that 1 = (1/1), and that you can shift things to either side of the equals sign, by changing the sign with the side.
You know that sin 45 = (root 2)/2 from your unit circle. If you don't know what this is, life is a little harder.

what an unecessarily complicated way of doing a very simple thing

it's a lot easier and makes a lot more sense to do it like this:

[WhoDa?]

That is officially my proof that I am older than 10, at WhoDa.

Why is that directed to me?

[Muzzles56]

Back in my day, in maths we added the stick to the bunny hole and got a baby rabbit

[Antallion]

sine rule yay. You'll use it now and never have to use it again in later classes.

[SupremeCommander]

Nu its copypasta
Mmmmmm pasta

It really isn't.

what an unecessarily complicated way of doing a very simple thing

it's a lot easier and makes a lot more sense to do it like this:

Its all very well, but, seeing as he didn't use a graphics calculator to solve for A, which we always did in high school, I went for the long way which teachers like, and assumed he didn't have a calculator at all.
Besides, mine refers to the unit circle, and gets an answer in whole values, not decimals.
If we answered in decimals in university/high school calculus we got failed, and you would have got failed for that too, as it likely asks for an exact answer.

You used inverse sine at the end of yours, which is all very well, but you rounded, which immediately introduces some error. In my school, they always asked for the /exact/ value, which is, half of the time, a square root. Your answer would have technically been: 20.67091869... etc. which is no good for exaction.  My 'unnecessarily complicated' way leads to a nice and simple answer.

The unit circle is sensible anyway, and is what trigonometric identities are built off, and you have to learn it anyway.