1. Jun 7, 2012

### darshanpatel

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

Find x in radians using [0,2pi]

Sin(3x)= -0.1658

2. Relevant equations

-None-

3. The attempt at a solution

3x=Sin-1(-0.1658)

x=sin-1(-0.1658)/3

x= -0.055523061

The teacher gave me a whole page to do the problem, so I don't know if there should be more work or not. Not positive if this answer is correct also.

2. Jun 7, 2012

### Villyer

I believe that there should be 6 answers to this equation.

3. Jun 7, 2012

### darshanpatel

Ok, could you help me get them? I don't understand this question at all.

4. Jun 7, 2012

### Villyer

Your work was all right, and your answer is in fact a zero of the equation. But it doesn't lie in the domain you are looking for.

When solving these equations, think of the unit circle.
sin and the height of the circle are related. So solving for when the sin(x) = -.1658, can you see how many solutions are?

5. Jun 7, 2012

### Staff: Mentor

Here are some hints:

sin (pi - θ) = sinθ
sin(2n*pi-θ)=-sinθ
plus other similar relations

chet

6. Jun 7, 2012

### darshanpatel

I still don't understand. If I could get the answers, I could try back-tracking to get the work and understand how to do it.

7. Jun 7, 2012

### Muphrid

You need to think logically about your answer; it's not in the range 0 to 2pi. You have a negative angle that has this sine. What positive angles in the range 0 to 2pi will have that sine?