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: Need some suggestions.

  1. Sep 4, 2006 #1
    Hey... Im kinda got stuck with this problem... can you guys give me a hint or something...

    Problem says:

    The tangentline to the curve y=1/3 x^3 - 4x^2 + 18x + 22 is parallel to the line 6x - 2y = 1 at 2 points on the curve... find the 2 points.

    Well I was thinking about writing the function for another line which has the same lope with the one given... so it should be something like y = 3x + m

    Now what?

    Thanks for your help.
  2. jcsd
  3. Sep 4, 2006 #2


    User Avatar
    Science Advisor
    Homework Helper

    You don't need to write an equation for another line, you just have to know what the slope of 6x - 2y = 1 is. Then you need to find an equation for the slopes of the lines tangent to your cubic curve. Then you have to solve (a quadratic) for when the slopes of the tangents equal the slope of 6x - 2y = 1.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook