Question

Evaluate the difference quotient for the given function. Simplify your answer.

f(x)=1/x, (f(x)-f(a))/(x-a)

Answer 1

(f(x)-f(a))/(x-a)
= (1/x - 1/a)/(x-a)
= ( (a - x)/(ax) )/(x-a)
now (a-x)/(x-a) = -1
so ..
= -1/(ax)