Number of real solutions to x/100=sinx

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In summary, the conversation discussed the problem of finding the number of real solutions to the equation x/100 = sinx and suggested using graphing to count the intersections. However, it was acknowledged that this method may not be practical. The question of when x/100 becomes greater than sinx was posed, with the hint that the answer is 100. It was also suggested to look at each successive interval of length pi/2 starting from 0.
  • #1
jason177
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I'm wondering if anyone here knows how to approach a problem like this:

The number of real solutions to the equation x/100 = sinx is...

I know I could always graph them and and count the number of intersections but that isn't really practical.
 
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  • #2
jason177 said:
I know I could always graph them and and count the number of intersections but that isn't really practical.
Try it anyways -- maybe you'll figure out a way to speed up the process along the way, or otherwise discover something useful?
 
  • #3
when does x/100 become greater than sin x? (hint: the answer is 100)

What happens at each successive interval of length pi/2, starting from 0?
 

1. How do you solve the equation x/100=sinx?

To solve this equation, we need to use algebraic manipulation and trigonometric identities. First, we can multiply both sides by 100 to get rid of the fraction. This gives us x = 100sinx. Then, we can use the identity sinx = x - x^3/3! + x^5/5! - ... to expand the right side. Finally, we can solve for x using algebraic techniques.

2. How many solutions does the equation x/100=sinx have?

This equation has an infinite number of solutions. Since sinx has an infinite number of values, the right side of the equation can take on an infinite number of values, resulting in an infinite number of solutions for x.

3. Can we use a calculator to find the solutions to x/100=sinx?

Yes, we can use a calculator to approximate the solutions to this equation. However, due to the infinite number of solutions, the calculator will only give us a few decimal places, and we would need to use algebra to find the exact solutions.

4. Are there any restrictions on the values of x for this equation?

Yes, there are restrictions on the values of x for this equation. Since x/100 cannot be greater than 1 or less than -1, the values of x must be between -100 and 100. Additionally, since sinx is periodic, there are an infinite number of values of x that will produce the same solution.

5. Is there a way to graph this equation?

Yes, we can graph this equation by plotting the points (x, x/100) and (x, sinx) on a coordinate plane. The points where the graphs intersect will represent the solutions to the equation. However, since there are an infinite number of solutions, the graph will show a continuous line rather than distinct points.

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