Intermediate Value Theorem and Rolle's Theorem to show root

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SUMMARY

The discussion centers on using the Intermediate Value Theorem and Rolle's Theorem to demonstrate that the function f(x) = 2x - 2 - cos(x) has exactly one root. The key steps involve evaluating the function at specific points, particularly f(0) and f(π), to establish the existence of a root. The conclusion drawn is that since the function crosses the x-axis only once, it confirms the presence of a single root, as per the implications of Rolle's Theorem regarding multiple roots.

PREREQUISITES
  • Understanding of the Intermediate Value Theorem
  • Familiarity with Rolle's Theorem
  • Basic knowledge of trigonometric functions, specifically cos(x)
  • Ability to evaluate functions at specific points
NEXT STEPS
  • Study the Intermediate Value Theorem in detail
  • Explore Rolle's Theorem and its applications
  • Practice evaluating functions at critical points
  • Investigate the behavior of trigonometric functions in root-finding problems
USEFUL FOR

Students studying calculus, particularly those focusing on root-finding techniques and the application of theorems in real analysis.

Wessssss
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Homework Statement


Use the Intermediate Value Theorem and Rolle's Theorem to show that f(x) = 2x-2-cosx has exactly one root.


Homework Equations





The Attempt at a Solution


I'm not really sure what the question is asking for. the theorems I believe are to prove the existence of a point between a closed interval, but I have no interval, and what does it mean by "one root"
 
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Wessssss said:

Homework Statement


Use the Intermediate Value Theorem and Rolle's Theorem to show that f(x) = 2x-2-cosx has exactly one root.

The Attempt at a Solution


I'm not really sure what the question is asking for. the theorems I believe are to prove the existence of a point between a closed interval, but I have no interval, and what does it mean by "one root"

Hint: Check f(0) and f(pi). And "one root" means the graph touches the x-axis only once. And if you find one root, what can you conclude from Rolle's theorem if you have another root?
 

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