Proving inequality with mathematical induction

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SUMMARY

This discussion focuses on proving the inequality 5k+1+9 < 6k+1 using mathematical induction. The key approach involves leveraging the inductive hypothesis that 6k+1 = 6*6k > 6*(5k+9). The proof is structured by demonstrating that 5k+1 + 9 < 6(5k+9) simplifies correctly, confirming the validity of the inequality. The steps outlined provide a clear method for tackling similar problems in mathematical induction.

PREREQUISITES
  • Understanding of mathematical induction principles
  • Familiarity with inequalities and algebraic manipulation
  • Knowledge of inductive hypothesis application
  • Basic proficiency in algebraic expressions and simplification
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  • Study the principles of mathematical induction in detail
  • Practice proving inequalities using mathematical induction
  • Explore examples of inductive proofs in textbooks or online resources
  • Learn about common pitfalls in mathematical induction proofs
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Students, educators, and anyone interested in mastering mathematical induction techniques, particularly in proving inequalities.

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I am having trouble proving these. I cannot figure out how to get to the conclusion. Here is my attempt. The stuff in red is just side work and is not part of the proof. I always get stuck on these types of problems, can someone offer some tips on how to approach these kind of problems in general? Should I start with the right hand side or the left hand side of the inequality?

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The goal is to show that 5k+1+9<6k+1. A good place to start is to note that 6k+1 = 6*6k > 6*(5k+9) by the inductive hypothesis like your sidework does. Then it suffices to show that
5k+1+9 < 6(5k+9)
 
I think I got it. So,
5k+1 +9 < 6(5k+9)
5*5k + 9 < 6*5k + 54
5*5k < 6 * 5k since 5 < 6
5*5k + 9 < 6 * 5k + 54 since 9<54

Does this look right?
 

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