posted by Mike .
John owns a hotdog stand. He has found that his profit is represented by the equation P(x)=x^2 + 12x + 46, where x is the number of hotdogs. What is the most he can earn?
Looks like he's in a good business. The more he sells, the more profit he makes, there's no limit. The minimum is $46 when he doesn't sell any hot dog. If he sells 10 hot-dogs, he makes $220 more!
Check the sign of the x^2 term!