Geometry curriculum question- exponential and decay functions

Discussion in 'Secondary Education' started by chessimprov, May 23, 2010.

  1. chessimprov

    chessimprov Rookie

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    May 23, 2010

    Should I be showing formulas like y = a(1+r)^ t when going over exponential and decay functions? It does not seem so because I do not find it in any Geometry book I haver so far. Seems like more of a pre-calc thing. Not that I do not want to enrich them, but there seems to be more than enough material to try to cover anyway.
     
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  3. Aliceacc

    Aliceacc Multitudinous

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    May 23, 2010

    Check your state standards.

    My sophs haven't seen exponential functions yet, so it would be too much of a stretch.

    We teach that in Precalc.
     
  4. Muttling

    Muttling Devotee

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    May 23, 2010

    We introduce exponential growth/decay in Algebra I and again in Algebra II.

    If you're asked to teach it in geometry (which there is a lot of algebra in geometry), I would certainly present the equations behind the graph.

    On a side note, this is my favorite subject to teach and it is very easy to teach with real world examples such as....

    Growth of Savings Account/Retirement Account Interest
    Decay of Radioactive Materials
    Decay of Drug Concentrations in the Body
    Decay of Car Values
    Growth of the U.S. National Debt
    Growth of Bacterial Cells
    etc
     
  5. chessimprov

    chessimprov Rookie

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    May 23, 2010

    y = a(1+r)^ t
    is actually more related to geometric sequences. But I still don't think I learned these formulas until pre-calc. I don't have much to work with in terms of state standards except for this TechPaths website and whatever objectives are mentioned on the online textbook, EPIC. So, it's very confusing and I have to keep constantly making judgment calls.
     
  6. Muttling

    Muttling Devotee

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    May 23, 2010

    y = a(1+r)^ t

    Technically speaking, that is the compound interest equation. a is the starting amount, r is the interest rate and t is the number of compounding periods.


    You are quite correct in that this is a judgement call. I wish you well.
     

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