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: Calculus - find dy/dt thank you

  1. Apr 6, 2005 #1
    calculus -.. find dy/dt...thank you..:(

    can someone plz help me out with this question...i did it all sorts of way,quotient rule, product rule..etc.. but i can never match the answer in the book..i just wanna know if u did..

    find dy/dt = x^2 Tanx / sec x

    The answer in the book was
    x(xcosx + 2sinx)

    lemmi know how you did it with a couple steps! thanks soo mcuh
  2. jcsd
  3. Apr 6, 2005 #2
    Do you mean find

    [tex] \frac{d}{dx} \frac{x^2 \tan{x}}{\sec{x}}[/tex]


    If so, here:

    [tex]\frac{x^2 \tan{x}}{\sec{x}} = x^2\tan{x}\cos{x} = x^2 \frac{\sin{x}}{\cos{x}}\cos{x} = x^2 \sin{x}[/tex]

    I'm sure you can take the derivative from there~ :smile:
  4. Apr 6, 2005 #3
    Damn you Data! :smile:
  5. Apr 6, 2005 #4
    got to be quick :tongue:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook