1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Related Rates

  1. Apr 24, 2005 #1
    Hi Again,

    I am doing a question on related rates that I have become stuck on.

    The height (h) of an equilateral triangle is increasing at a rate of 3cm/min. How fast is the area changing when h is 5cm?

    I know that the area of a triangle is bh/2, but after that I am stuck :redface: I tried deriving it using the chain rule so that I could substitute h and the rate of h, but I don't think that i was doing it the right way. If anyone could direct me here I would really appreciate the help.
     
  2. jcsd
  3. Apr 24, 2005 #2
    Here are some things to consider, the height "h" of an equilateral triangle is

    [tex]\frac{1}{2}\sqrt{3}s[/tex]

    where "s" is the length of one side.

    The area of this triangle is equal to

    [tex]\frac{1}{2}sh[/tex]

    See any substitutions?
     
  4. Apr 24, 2005 #3
    [tex]
    \frac{dA}{dt} = \frac{dh}{dt} * \frac{dA}{dh}
    [/tex]
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Related Rates
  1. Related Rates (Replies: 3)

  2. Related Rates (Replies: 16)

Loading...