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!

Continuous function

  1. Oct 19, 2007 #1

    f(x) =

    2x + 1, for x =< (greater than or equal to) 2
    .5x^2 + k for x > 2


    FOR what value of k will f be continuous ?

    MOST IMPORTANTLY, if k=4, is f differentiable at 2?
  2. jcsd
  3. Oct 19, 2007 #2
    you're going to have to try a little harder than that
  4. Oct 19, 2007 #3
    why would you even respond if youre going to be rude?

    i already did it i just wanted to see what other people got

    at K = 3 it should be continuous and i think at k=4 it will be differentiable because the derivative from the left = 2 and the derivative from the right will be x or in this case 2

  5. Oct 20, 2007 #4
    continuous for k=3.
    because both functions have the same value @ x=2 and therefore the graph doesn't have a "jump" or a "step". More precisely, the limit @ x=2 (the transition point) is equal to some number.

    for k=4, check at x=2.

    if both equations are not equal then you cannot differentiate at that point.
  6. Oct 20, 2007 #5
    i wasn't being rude because you're being ignorant. 1 this isn't the hw forum ,2 we don't do your homework for you, 3 i can't read your mind and know you've already done the problem.
  7. Oct 20, 2007 #6
    i am in calculus therefore i am ignorant!
  8. Oct 21, 2007 #7
    i really don't think that's the reason he thinks ur ignorant, its cuz u posted HW problems on the NOT-HW forum. THe calculus/analysis forum will tolerate help being asked for problems but generally not of this sort because it is somewhat formulaic. When I ask for help here I detail my solution (and i usually have a complete one at the time of posting). One typically asks for feedback on an idea they might have.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Continuous function
  1. Continuous Function (Replies: 5)

  2. Continuous function? (Replies: 6)

  3. Continuous functions (Replies: 3)

  4. Continuous function (Replies: 8)