Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Limits and estimating slope

  1. Feb 16, 2006 #1
    Hey there, I need a little push in the right direction.
    Here is the question:
    The slope of the tangent line to the graph of the exponential function
    y=2^x at the point (0,1) is lim x approaches 0 (2^x-1)/x.
    Estimate the slope to three decimal places.
    Where I am getting confused is which formula do I plug (x) into to find a secant slope?
    I hope I asked the right question.
  2. jcsd
  3. Feb 16, 2006 #2


    User Avatar
    Science Advisor

    Yes, since you are only asked to "estimate the slope to three decimal places" you just need to plug a small enough x into that secant formula which is exactly what you wrote: (2x-1)/x. That should take about 5 seconds using a calculator!

    (Finding the limit itself in order to find the actual formula is much harder!)
  4. Feb 17, 2006 #3
    Thank you for your help
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook