Question

Please Help!!
What are the restrictions on the following expressions?

x^2 + 6x - 27 divided by x + 9

Answer 1

x cannot equal -9 . If you plug in x = -9 into the expression, you get division by zero making it undefined. Note that x^2+6x-27 = (x+9)(x-3) and the x+9 in the numerator can 'cancel' with the x+9 in the denominator. If this is a function, then x = -9 is still not allowed in the domain as we will get a hole in the graph, but not a vertical asymptote.

Answer 2

Thank you