posted by Alley on .
Use the intermediate theorem to show that the polynomial function value has a zero in the given interval
Find the value of f(1.6)
Find the value of f(1.8)
My calculator gave me a negative value for f(1.6)
and a positive value for f(1.8)
I wonder how the graph got from below the x-axis to above the x-axis in that little interval.
What does that mean?
I plugged in x = 1.6 and got some negative value
I plugged in x = 1.8 and got some positive value
so we have two points of your graph
one is (1.6, -?) , the other is (1.8, + ?)
so one is below the x-axis , the other is above the x-axis
make a rough sketch of this situation, (it doesn't make any difference how far down or how far up you place points)
join your two points.
I see them crossing or intersecting the x-axis.
Don't we call the place where a graph cuts the x-axis, "the zero of the function" ??
I see such a point between x = 1.6 and 1.8