I am trying to simplify a difference quotient with the form
f(x+h)−f(h)/h
if f(x)=2/x2 I have attempted to cancel out the denominator of the numerator by the least common denominator method. I know that I can solve this using implicit differentiation, but am trying to use the difference quotient to get the partial derivative
Here is my work so far:
f(x+h)−f(x)(h)
=f(2/(x+h)2)−f(2/x2)h
=(2/(x+h)2)−(2/x2)h
here I multiply by the LCD
=(2(x2)−2(x+h)2)/(x2(x+h)2)h
Here I expand out the top and cancel out 2x2
=(2x2−(2x2+4xh+2h2))/(x2(x+h)2)h
=−(4xh+2h2)/(x2(x+h)2))h
Here I think I should multiply by 1/h to get rid of the h on the bottom
I end up with:
=4xh+2h2hx2(x+h)2
factor out an h
=−4x+2hx2(x+h)2
