Ms Coombs presents the students with a
factored form for a polynomial that includes
repeated factors:
y = (x – 2)(x – 2)(x – 5)(x – 7). She
does this to illuminate that functions do
not always pass through a zero with a change
in sign.
Continuing from the previous clip, Ms.
Coombs works with the given function.
Here, she allows the students to hypothesize
and refine each other’s ideas for how to
modify the question to make the function
negative on both sides of x=2.
Ms Coombs has the students consider that an
alternative form for
y = (x – 3)(x + 1)(x + 4) might
exist. To do this, she uses the
“graphing calculator” program to expand the
factored form.
Day 2 - Clip 1
Ms Coombs begins this unit by guiding a
discussion about a function in factored
form. The function she chooses to use is
y=(x-1)(x-2)(x-3)(x-4). Specifically, Ms Coombs
focuses on the function outputs as the inputs
approach x=1.
