# Homework Help: Can't solve this equation

1. Dec 24, 2011

### ISX

1. The problem statement, all variables and given/known data

3. The attempt at a solution
I am trying to solve for A but the sine thing has me all screwed up. This isn't for homework but I figured it might be better in this section. I get down to Sin A(4.625A + 171.87) = 229.16

I don't think I did it right at all and if I did I have no idea how to go any farther with it. Thanks for any help you guys might have.

2. Dec 24, 2011

### rock.freak667

You can't really solve that algebraically unless you know some information about A. But what you can do is use a graph plotter and use that to get your values of A. You can use WolframAlpha.

3. Dec 24, 2011

### SammyS

Staff Emeritus
I believe this can only be solved numerically, or graphically.

Like many trig. equations, there are many solutions.

4. Dec 24, 2011

### ISX

Well that explains why I couldn't get any further then lol. I can do a trial and error of A and that will be close enough for what I am doing, just figured I would get an exact number but if it will take something like that then I can wing it just as well. It's not something that has to be accurate exactly, it's just something that needs to be under a certain tolerance, as long as what I put in for A makes the output less than the tolerance it will work.

Thanks for the help!

5. Dec 27, 2011

### Ray Vickson

If SIN A means a number SIN times the number A, then you can convert this to a quadratic equation in A and solve it using standard formulas. However, if SIN A means the trigonometric function sin(A), then you have an equation that can only be tackled numerically.

RGV