Question

The elevation E, in meters, above sea level at which the boiling point of a certain liquid is t degrees Celsius is given by the function shown below. What elevation is the boiling point 79.5 degrees? 80 degrees?
E(t)=1100(80-t)+500(80-t) ^2

At what elevation is the boiling 79.5?

Answer 1

Given function is 

$E(t) = 1100(80 - t) + 500(80 - t)^2$

At t= 79.5 degree.

So we can place t= 79.5 in given equation

$E(79.5) = 1100 (80 - 79.5) + 500* (80 - 79.5)^2$
                    = $1100 * 0.5 + 500 * (0.5)^2$
                     = $550 + 500 * 0.25$
                    = $550 + 125 = 625$

So elevation equal to 625 meter at t = 79.5 degree.