Number of real solutions to x/100=sinx

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SUMMARY

The equation x/100 = sin(x) has a finite number of real solutions, specifically determined by the intersections of the linear function and the sine function. The critical point occurs when x/100 exceeds the maximum value of sin(x), which is 1, at x = 100. Analyzing the behavior of the functions within intervals of length π/2 reveals the periodic nature of sin(x) and helps in estimating the number of solutions. Graphical methods can supplement analytical approaches for a comprehensive understanding of the intersections.

PREREQUISITES
  • Understanding of trigonometric functions, specifically sine.
  • Familiarity with linear equations and their graphical representations.
  • Knowledge of periodic functions and their properties.
  • Basic skills in graphing functions or using graphing calculators.
NEXT STEPS
  • Explore the properties of sine functions and their periodicity.
  • Learn about graphical methods for solving equations, including intersection counting.
  • Investigate numerical methods for finding roots of equations, such as the Newton-Raphson method.
  • Study the implications of function behavior in intervals, particularly for periodic functions.
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Mathematics students, educators, and anyone interested in solving trigonometric equations or understanding the intersection of linear and periodic functions.

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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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?
 
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?
 

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