PLEASE HELP. WILL FAN AND MEDAL.
During a manufacturing process, a metal part in a machine is exposed to varying temperature conditions. The manufacturer of the machine recommends that the temperature of the machine part remain below 141F. The temperature T in degrees Fahrenheit x minutes after the machine is put into operation is modeled by T = 0.005x2 + 0.45x + 125. Will the temperature of the part ever reach or exceed 141F? Use the discriminant of a quadratic equation to decide.
A. yes
B. no

Question

PLEASE HELP. WILL FAN AND MEDAL.
During a manufacturing process, a metal part in a machine is exposed to varying temperature conditions. The manufacturer of the machine recommends that the temperature of the machine part remain below 141F. The temperature T in degrees Fahrenheit x minutes after the machine is put into operation is modeled by T = 0.005x2 + 0.45x + 125. Will the temperature of the part ever reach or exceed 141F? Use the discriminant of a quadratic equation to decide. 
A. yes 
B. no

anonymous · Answer

The discriminant of a number is (b^2)-4ac.  a is the highest degree coefficient, b is the second highest degree coefficient, and c is the next highest degree coefficient.
In this case the discriminant would be 
.45^2-4*.005*125
=-2.2975.
Then plug that number into the equation for x to see if it is higher then 141
.005(-2.2975^2)+.45(-2.2975)+125
=123.94
so no