Maximum number of daily sales - Can somebody walk me through

[tc1227]

A company notices that after a marketing push, sales immediately increase but then decrease as time passes. If the number of daily sales (t) days after the push is represented by the equation:

S = 3t^2 + 30t + 100

what is the maximum number of daily sales?

 

[tkhunny]

Re: Maximum number of daily sales - Can somebody walk me thr

You missed something in there. Perhaps a negative sign on the '3'?

Did you learn anything about a "parabola" or "completing the square"? You could need those.