Results 1 to 4 of 4

Math Help - Equation of the Tangent Line

  1. #1
    Newbie CCadavid's Avatar
    Joined
    Oct 2010
    Posts
    2

    Unhappy Equation of the Tangent Line

    Find the Equation of the tangent line for the curve:
    Equation of the Tangent Line-untitled.jpg at the point ( 3, 0.6 )

    I already know the derivative is -4/25 but everytime I do it the answer comes out

    y= -4/25 x +19/25 and I know that's wrong. Could someone please show me the work and the right answer???
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    12,062
    Thanks
    902
    Quote Originally Posted by CCadavid View Post
    Find the Equation of the tangent line for the curve:
    Click image for larger version. 

Name:	Untitled.jpg 
Views:	37 
Size:	4.1 KB 
ID:	19407 at the point ( 3, 0.6 )

    I already know the derivative is -4/25 but everytime I do it the answer comes out

    y= -4/25 x +19/25 and I know that's wrong. Could someone please show me the work and the right answer???
    why don't you show what you did and maybe someone can spot your mistake?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,236
    Thanks
    28
    Quote Originally Posted by CCadavid View Post
    I already know the derivative is -4/25 but everytime I do it the answer comes out

    What is your gradient function?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Senior Member Educated's Avatar
    Joined
    Aug 2010
    From
    New Zealand
    Posts
    433
    Thanks
    12
    Quote Originally Posted by CCadavid View Post
    Find the Equation of the tangent line for the curve:
    Click image for larger version. 

Name:	Untitled.jpg 
Views:	37 
Size:	4.1 KB 
ID:	19407 at the point ( 3, 0.6 )

    I already know the derivative is -4/25 but everytime I do it the answer comes out

    y= -4/25 x +19/25 and I know that's wrong. Could someone please show me the work and the right answer???
    You know that the tangent equation is in the form of y = mx + C where C is a constant.

    Since you know the gradient, all you have to do is solve for C by substituting in your values.

    Therefore you will have the equation:

    y = (\frac{-4}{25})x + C

    0.6 = (\frac{-4}{25}) \times 3 + C

    0.6 = -0.48 + C

    0.6 + 0.48 = C

    C = 1.08

    And so your equation will be: y = (\frac{-4}{25}) x + 1.08
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Equation of a tangent line
    Posted in the Calculus Forum
    Replies: 1
    Last Post: October 3rd 2011, 11:52 AM
  2. Replies: 6
    Last Post: January 12th 2011, 03:38 PM
  3. Equation of a line tangent
    Posted in the Calculus Forum
    Replies: 3
    Last Post: July 26th 2009, 06:25 PM
  4. tangent line equation
    Posted in the Calculus Forum
    Replies: 6
    Last Post: April 10th 2008, 02:29 PM
  5. equation of the tangent line
    Posted in the Calculus Forum
    Replies: 3
    Last Post: October 16th 2007, 02:47 PM

Search Tags


/mathhelpforum @mathhelpforum