Answer:
-2 and 4
Step-by-step explanation:
When you look for values that make an expression “illegal” the first step is to look for 3 things.
1) a variable in a denominator
- we have b, a variable, in the denominator of this expression
- values in the denominator cannot be 0
2) variables under even roots
- variables under even roots are a restriction because even roots are undefined when there are negative values under them
- there are no roots in this case so we dont have to worry about that
3) the literal letters: “log” in the expression
- there’s no “log” in the expression so we dont have to worry about that
—moving on—
We have a variable in the denominator, b.
The expression is a quadratic:
b^2 - 2b - 8
You have to find values that make this quadratic 0.
So you can make an equation setting the quadratics equal to 0.
b^2 - 2b - 8 = 0
Solve for b
Factor:
(b - 4)(b + 2) = 0
Because of zero product property we can say:
b = -2, b = 4.
If these values are plugged into your expression, it will be “illegal,” or “undefined,”
