Question 331439
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*[tex \LARGE \ \ \ \ \ \ \ \ \ \ d(V)\ =\ \frac{V^2}{20}\ +\ V]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 150\ =\ \frac{V^2}{20}\ +\ V]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 150\ -\ V=\ \frac{V^2}{20}]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 3000\ -\ 20V=\ V^2]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ V^2\ +\ 20V\ -\ 3000\ =\ 0]


Use the quadratic formula since it doesn't factor neatly.  Also, toss out the negative root since *[tex \Large V\ \geq\ 0] is specified.


John
*[tex \LARGE e^{i\pi} + 1 = 0]
My calculator said it, I believe it, that settles it
<img src="http://c0rk.blogs.com/gr0undzer0/darwin-fish.jpg">
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