Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

monroe17

  • 3 years ago

Find an equation of the tangent line to the curve at the point. x^2+xy+y^2=7 (2,1) please show steps! I need to learn how to do it

  • This Question is Closed
  1. ChmE
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Have you been taught derivatives

  2. monroe17
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yes, but tomorrow I have an exam on a bunch of stuf and im sooooooo lost!!! I'm just trying to learn it all because I don't understand my professor at all.

  3. ChmE
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    okay lets start with this problem. Every time you take the derivative of a y we need to add y'. Ex) the derivative of 2y^2=6 is 4yy'=0, then you solve for y' We will do the same above. Let's work one term at a time. What is the derivative of x^2?

  4. monroe17
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    2x

  5. timo86m
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Do implicit differentiation in this one i suppose. do it for both y and x

  6. monroe17
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    thats the prob idk how

  7. timo86m
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \[-{\frac {x+2\,y}{2\,x+y}}\]

  8. timo86m
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    http://www.khanacademy.org/math/calculus/differential-calculus/v/implicit-differentiation this could help

  9. timo86m
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    http://www.khanacademy.org/math/calculus/differential-calculus/v/implicit-differentiation--part-2 part 2 is nice too

  10. timo86m
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    well when y is dependant variable -(2*x+y)/(x+2*y)

  11. timo86m
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    at 2,1 the slope is -5 -- 4

  12. monroe17
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I figure it out. But, now I'm stuck on the next problem

  13. timo86m
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    use y=mx+b 1=-5/4*2+b sfb

  14. timo86m
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    b=7/2 so y=-5/4*x+ 7/2 :)

  15. timo86m
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    BTW I graphed it and it works fine both the tangent line and the function yyou gave me do you wanna see it?

  16. monroe17
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yeah i already figured it out

  17. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy