The power P delivered to a load by a current of i amperes through a resistance of 19 ohms, when 110 volts are supplied at one end of the line, is given by the formula P = 110i - 19i2 . Determine the maximum power that can be delivered.

maximum power in watts =

My Answer:
My answer is:

P=110i-19i^2
P'=110-38i
0=110-38i
i=2.8947
P"=-38 therefore a max

Max Power in watts = 2.8947

can you please confirm this is correct. Thanks

4 answers

no, maximum power is P(2.8947) = 159.211
ok. I understand that you took the value and plugged in for i. But can I ask why...
because they asked for maximum power, not the current which produces maximum power. Just because you arrive at an answer, that does not mean you have answered the question.
Ok.... great. thank you Steve. I know understand!