Help me pls!
-5i^2 + 120 i = P will be max at i = -b/2a where a = -5 b = 120
max will be at i = -120 / (2* (-5)) = 12 amps
Another way to get the answer:
To find the maximum, find the first derivative and set it equal to zero.
Problem: P = 120·i - 5·i2
First derivative: P' = 120 - 10i
Setting the first derivative to zero: 120 - 10·i = 0
-10·i = -120
i = 12 amps