Post a New Question


posted by .

Find f'(a).

f(x)= (x^2 + 1)/(x - 2)


[[(a + h)^2 + 1]/[(a + h) - 2]] - [(a^2 + 1)/a - 2] and the whole thing divided by h

I tried simplifying it and ended up with [a + h/-2] - (a-2), which is incorrect. I used wolfram alpha and got (a^2 - 4a - 1)/(a - 2)^2 but I do not know how to get this. Please help.

  • Calc -

    (a^2+2ah+h^2+1)(a-2) -(a^2+1)(a+h-2)

    a^3+2a^2h+ah^2+a-2a^2-4ah-2h^2-2 -a^3-a-a^2h-h+2a^2+2

    that is
    a^2h + ah^2 -4ah -h

    divide numerator by h
    a^2 +ah -4a -1
    let h-->0
    a^2-4a-1 sure enough now denominator
    let h-->0
    (a-2)^2 sure enough

Answer This Question

First Name:
School Subject:

Related Questions

More Related Questions

Post a New Question