Posted by Soroban on September 22, 2002 at 09:36:50:
In Reply to: i've got another one posted by Heather on September 21, 2002 at 22:57:51:
: the equation W= 120I- 12I^2 represents the power (W), in watts, of a 120-volt circuit having a resistance of 12 ohms when a current (I) is flowing through the circuit. what is the maximum power, in watts, that can be delievered in this circuit?
Heather,
What course are you in?
1) If it is beginning Calculus, then you already know about derivatives
and how they are used to maximize/minimize functions.
Okay, big hint: set dW/dI = 0.
2) If this is a pre-Calculus course, I suggest you locate the vertex
of the parabola.