
Patrick B. answered 05/28/20
Math and computer tutor/teacher
1. The demand line as a function of price has points (0,50) and (10,0);
[50 given away and none sold when price is $10]
2. The equation of the demand line...
slope is m=50/-10 = -5
The intercept, using (10,0) is B = y - mx = 0 - (-5)(10) = 50
S(p) = -5p + 50
3. Revenue function R(p) = p (-5p+50) = -5p^2 + 50p
4. graph functions at desmos dot com
5. 0 = p(-5p + 50)
p=0 or -5p + 50 = 0
p=0 or p=10
You make no money if given away for free, or if price is $10, as giv en
6. Maximizing the revenue function:
7. A=-5 B=50
8. max occurs at -B/(2a) = -50/-10 = 5
R(5) = 5( -5*5+50) = 5 ( 25)= 125
max revenue of $125 when price is $5
9. -5p^2 + 50p>50
-5p^2 + 50p - 50 > 0
p^2 - 10p + 10 < 0
From the graph,
$50 revenue between p=1.18 and 8.88