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.
We can simply observe that.
- 0.777... is rational, because it is a number with infinite but repeating decimal part.
- 1/3 is rational, because it's the division between two integers
, so this is rational as well.
Since the product of two rational numbers is always rational, we have that
are all rationals, since they are the product of two rationals.
On the other hand, we have
and thus
which is irrational.
Answer:
Step-by-step explanation:
× 
( multiply values on numerators/ denominators together )
= 
=
