Using the Factor Theorem, it is found that:
a) The function that models the temperature over time is: f(x) = 0.096x² - 2.375x + 9.6.
b) The minimum temperature is of -131.41ºC.
<h3>What is the Factor Theorem?</h3>
The Factor Theorem states that a polynomial function with roots(also called zeros)
is given by the following rule.

In which a is the leading coefficient of the polynomial, determining if it is positive(a positive) or negative(a negative).
The roots of the function are when f(x) = 0, hence for this problem the are given as follows:
x = 5, x = 20.
Two roots, hence the equation is a parabola given as follows:
f(x) = a(x - 5)(x - 20)
f(x) = a(x² - 25x + 100).
When x = 0, y = 9.6, hence the leading coefficient is found as follows:
100a = 9.6.
a = 9.6/100
a = 0.096.
Then the equation is:
f(x) = 0.096(x² - 25x + 100)
f(x) = 0.096x² - 2.375x + 9.6.
The coefficients are:
a = 0.0096, b = -2.327, c = 9.6.
Hence the minimum temperature is the <u>y-coordinate of the vertex of the function,</u> given as follows:

More can be learned about the Factor Theorem at brainly.com/question/24380382
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