1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Mean value theorem for integrals.

  1. Oct 13, 2006 #1
    find c such that (f)average=f(c)

    f(x)=7sin(x)-sin(2x), [0,pi]

    ok so i found (f)average= 14/pi

    then i tried to compute:
    7sin(c)-sin(2c)= (14/pi)

    but the answers i got were wrong.
    please if someone could reply with some helpful information on how to solve this. thank you
     
  2. jcsd
  3. Oct 13, 2006 #2
    this is how i would start it:

    [tex] 7\sin c - \sin 2c = \frac{14}{\pi} [/tex]

    [tex] 7\sin c - 2\sin c \cos c = \frac{14}{\pi} [/tex].

    Let [tex] a = \sin c [/tex] and [tex] b = \cos c [/tex].

    Then [tex] 7a-2ab = \frac{14}{\pi} [/tex]. We also know that [tex] a^{2} + b^{2} = 1 [/tex]. Can you go from there?
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook




Loading...