A Nice Algebra Problem | Math Olympiad | How to solve for x?

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  • Опубликовано: 20 янв 2025

Комментарии • 14

  • @kateknowles8055
    @kateknowles8055 День назад +2

    SALogic, you have found and solved a neat little challenge here . Congratulations.
    I think that you enjoy the natural logarithms.
    One day I will be happy with the Lambert w bits also. But it looks complicated with so much algebra.

    • @RichieSarabia-ms2er
      @RichieSarabia-ms2er День назад +2

      Lambert W Function also know as product log

    • @SALogics
      @SALogics  17 часов назад +2

      Thanks for the tips! ❤

  • @kateknowles8055
    @kateknowles8055 День назад +1

    x=2 First solution that I discovered
    Checking: LHS = 2^(x-1) = 2^ (2-1) = 2^1 = 2 = x =RHS
    Next comment mentions another solution......thinking...
    x= 1 Second solution
    Checking: LHS = 2^(x-1) = 2 ^ (1-1) = 2^0 = 1 = x = RHS
    now to see what is happening here , can these be on a graph? * to show the solution values
    Plotting y = 2^(x-1) a set of points (0 , 0.5) , (0.5 , 1/sqrt(2) ) , (1, 1) * , (1.5 , sqrt(2)) , (2, 2 ) *, (2.5 , sqrt(8) , (3, 4)
    At x= 1.5 this function2^(x-1) has curved below the line y=x . The function is exponential , smooth and not as steep as y = e^x but is one place to the left of y= 2^x.
    With a little rearrangement, below: we can look along y =0 for solutions
    We could see a turning poiint if we looked at dy/dx of y = 2^(x-1) - x might be close to 1.5, - 0.1. If this is interesting it can be chased with a calculator
    or a chart could be added to a little spreadsheeting.

    • @SALogics
      @SALogics  17 часов назад +1

      Very nice! ❤

  • @musicsubicandcebu1774
    @musicsubicandcebu1774 День назад +1

    13:08 . . . why 4/4 and not any n/n?

    • @SALogics
      @SALogics  17 часов назад +1

      Because 4 = 2² ❤

  • @nasben8855
    @nasben8855 День назад +1

    How did u know about the two solutions

    • @SALogics
      @SALogics  17 часов назад +1

      Every equation of this type has two solutions! ❤

  • @shadrana1
    @shadrana1 10 часов назад

    2^(x-1)=x
    By observation,
    Try x=1
    2^(1-1)=1
    2^0=1, therefore x=1
    Try x=2
    2^(2-1)=2
    2^1=2, therefore x=2. solved in three minutes.
    If you draw a graph of the function,the solutions are x=1 and x=2.

  • @kajalbanerjee8220
    @kajalbanerjee8220 21 час назад +1

    2

    • @SALogics
      @SALogics  17 часов назад +1

      Very nice! ❤

  • @tomodul2619
    @tomodul2619 День назад +1

    X=1