Given:
The power generated by an electrical circuit (in watts) as a function of its current x (in amperes) is modeled by

To find:
The current which will produce the maximum power.
Solution:
We have,


Differentiate with respect to x.

...(i)
To find the extreme point equate P'(x)=0.


Divide both sides by -30.

Differentiate (i) with respect to x.

(Maximum)
It means, the given function is maximum at x=4.
Therefore, the current of 4 amperes will produce the maximum power.
1 ) the formula used to calculate the simple interest is
I = Ci*n, f his formula you obtain n , that is the time in years n = I/ Ci, where c is the initial capital, i is the earned interest , and i is he rate of interest,
n = 120/600 (0,025) = 120 / 15 = 8 , at 8 years, you will obtain $ 120 of INTEREST
Answer:

Step-by-step explanation:
Let's write this out as an equation. Let the unknown quantity be x:
