math

posted by .

If y= (x^2+20)/(x-4) Find all critical Numbers.

After get f' i got the answer -5/4. What did i do wrong or is that the critical number?

  • math -

    critical number: where y'=0 or y' undefined.

    Anyway, y' = (x^2-8x-20)/(x-4)^2

    y'=0 when x = -2,10
    y' undefined when x = 4

    how did you come up with -5/4 ?

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Math

    The critical numbers of the function: f(t)=7t^(2/3)+t^(5/3) f'(t)=14/3t^(-1/3)+(5/3)t^(2/3) I got 0 as a critical number but it is hard for me to factor the f'(t). Whats the other critical number?
  2. Calculus - another question

    "Find the absolute minimum value of the function f(x) = x ln(x)". I know that one of the critical values is 1 (domain restriction). Am I right?
  3. Math

    Find any critical numbers of the function. (Enter your answers as a comma-separated list.) g(x) = x^7 − 7x^5 Honestly, I have no idea how to find the critical number!
  4. Math

    2x^3+3x^2-120x to find the critical numbers I took the derivative which is 6x^2+6x-120 so divide by 6 to simplify x^2+x-20=0 so the critical numbers will be (4,0) and (-5,0) but its wrong I don't know y?
  5. Calculus

    If y= (x^2+20)/(x-4) Find all critical Numbers. After get f' i got the answer -5/4. What did i do wrong or is that the critical number?
  6. Critical Points, Etc.

    find the values for a, b, and c such that the function f(x)= x^3 + ax^2 + bx+ c has a critical point at (1,5) and an inflection point at (2,3). a= -6 b= 3 c= 7 i got those, but they're wrong. i'm not sure why. :/
  7. help please!

    f(x)=x+1/x Find all critical numbers. Find where the function is increasing and decreasing. Find critical points and identify each as a relative maximum, relative minimum, or neither. Find second order critical numbers and tell where …
  8. Calculus

    Please check, if there is something wrong please explain what I did wrong. Thank you! Calculate the d^2y/dx^2. y= e^-x + e^x y' = e^x - e^-x y'' = e^x + e^-x Find the x-coordinace of all critical points of the given function. determine …
  9. Math

    Consider the function y = 3x5 – 25x3 + 60x + 1. Find the critical points of this function. So I got 1 and 2 as the critical points..but I feel like I did something wrong, is this right?
  10. critical points

    (1 pt) Find all critical values for the function f(x) = 6 x^3 - 18 x + 1, and then list them (separated by commas) in the box below. List of critical numbers:

More Similar Questions