Answer:
$25.65
Step-by-step explanation:
135 (19%)
$25.65
We are going to solve this problem two ways:
Solution 1. Graphical
If you plot the equation of temperature
for x between 0 and 160 minutes you'll get the plot in the attachement.
The blue curve represents the variation of the temperature in time. Notice that it crosses the red line (132 degrees <span>Fahrenheit</span>) twice, at around 20 F and 70 F.
So the answer is yes, if will reach 132 F.
Solution 2. Analytical
In order to see if the variation of temperature y(x) intersects 132 F line means to solve the equation:
Step 1. Write the equation in the quadratic form:
Step 2. Calculate the discriminant:
Only by looking at the discriminant we can see that it is positive, which means that it crosses the 132 F line in two points, which also means that there are two roots of the equation, both real numbers.
Step 3 (optional). Calculate the roots of the equation.
As you can see, tha analytic solution matches the graphic solution. At time x=20.5 minutes the temperatures reaches 132 F and is still rising. At time x=69.5 minutes the temperature is again 132 F but this time is decreasing.
For the first 60 positive integers, a = 1, n = 60, l = 60.
Sn = n/2(a + l)
s = 60/2(1 + 60) = 30(61)
For the next 60 positive integer, a = 61, n = 60, l = 120
Sum = 60/2(61 + 120) = 30(61 + 120) = 30(61) + 30(120) = s + 3600
Sum of first 120 positive integers = s + s + 3600 = 2s + 3600