- #1
uradnky
- 30
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Homework Statement
The electric power in Watts produced is given by p= 144r/(r+.8)^2
where r is the resistance in ohms.
For what value of r is the power P a maximum?
Homework Equations
The Attempt at a Solution
Using the quotient rule i found a derivative of..
dp/dt= 144(-r+.8) / (r + .8)^3
Now I need to set this equal to zero and solve for R?
Multiplying the demonminator by 0 would leave me with just the numerator giving me..
-144r + 115.2 = 0
Solving for r gives me r = 0.8ohms
Was there maybe a problem with my derivative?