Sketch the graph of the following function and determine its domain and range.

Question

1. f(x)= x² - 81/ x+9

2. f(x)=√9-x²

3. f(x) = {x² -1 if x<3 at x= 3

{x+5 3≥x

Answer 1

#1 You need to clarify what is in the numerator; the domain is the whole real line except for x=-9.

If the numerator is (x²-81), then there is a removable discontinuity at x=-9.

#2 The answer depends on what is under the radical sign

#3 Your function is multiply defined for x<3!

Answer 2

This is my first attempt at a video reply, and I can make another if more explanation is required.

Here's the link to the desmos:

https://www.desmos.com/calculator/r92q1ytyr5