Answer:
(a) Graph : In attachment 
(b) Domain: (-∞,∞)
(c) Range: (-∞,∞)
Explanation:
Given: 

It is a linear function. 
For sketch:
Put x=3 into f(x) to get y 
f(3) = 2 - 3 = -1 
Point (3,-1) 
Put x=-3 into f(x) to get y 
f(3) = -2 - 3 = -5 
Point (-3,-5)
Plot the points on graph and join the points. Please find the attachment. 
For domain: 
It is input value of x where function is well defined. 
Domain: All real number 
For range: 
It is output value of y.
Range: All real number.