Video Transcript
If the graph of the quadratic
function 𝑓 cuts the 𝑥-axis at the points negative three, zero and negative nine,
zero, what is the solution set of 𝑓 of 𝑥 equals zero in the set of real
numbers?
Now remember, if we’re given the
graph of a function, we can find the solutions to 𝑓 of 𝑥 equals zero by locating
the 𝑥-intercepts or zeros of the function. Now, in this case, we’re not
actually given a graph, but we are told the coordinates at which the function cuts
the 𝑥-axis. It’s negative three, zero and
negative nine, zero. Since the first number in each
ordered pair corresponds to the value of 𝑥 here, we can say that the solutions to
the equation 𝑓 of 𝑥 equals zero are 𝑥 equals negative three and 𝑥 equals
negative nine. Using set notation, the solution
set of 𝑓 of 𝑥 equals zero in the set of real numbers is the set containing the
elements negative three and negative nine.
