1. f (x) = x²-4x
---------- =
x+1
= (x²-4x)[tex](x+1)^-1[/tex]
remember that (f)(g) = f'g+g'f
=[tex]\frac{2x-4}{x+1} - \frac{x^2 - 4x}{(x+1)^2}[/tex]
= [tex]\frac{x^2 +2x - 4}{(x+1)^2}[/tex]
2. f (x) = 3x
-------- =
x +4
= 3x[tex](x+4)^-1[/tex]
=[tex]3x(-(x+4)^2) + 3((x+4)^-1)[/tex]
=12/[tex](x+4)^2[/tex]
3. f(x)= x+1
---------- =
x³
=[tex](x+10)((x)^(-3))[/tex]
=[tex]x^(-3) - 3(x^(-4))(x+1)[/tex]
=[tex]\frac{-2x+3}{x^4}[/tex]
4. y = x²
--------- =
x+2x
multiply 1/x to the numerator and denominator
you get:
=[tex]\frac{x}{1+2)[/tex]
=[tex]\frac[1}{3} (\frac{d}{dx} x)[/tex]
=1/3
5 . f(x) = x-2
---------- =
x³
[tex]=(x-2)(x^(-3))
= x^(-3) - 3(x^(-4))(x-2)
=\frac{x-3x+6}{x^4}
=\frac{6-2x}{x^4}[/tex]
