Hi
profit P(x),in thousands of dollars, for a firm when it sells x thousand units
p(x)= -x^2+30x-50
a) What is the firm profit when it sells 1000 units: p(1) = 29-50 = -$21,000
b) What is the firms profit when it sells 10,000 units: p(10) = $150,000
c) how many units must the firm sell to break even: 1772 units
-x^2+30x-50 = -(x-15)^2 + 175
x = 1.77124, 28.22875
Solved by pluggable solver: SOLVE quadratic equation with variable |
Quadratic equation (in our case ) has the following solutons:
For these solutions to exist, the discriminant should not be a negative number.
First, we need to compute the discriminant : .
Discriminant d=700 is greater than zero. That means that there are two solutions: .
Quadratic expression can be factored:
Again, the answer is: 1.77124344467705, 28.228756555323.
Here's your graph:
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