1 Aug
2012
1 Aug
'12
4:35 a.m.
Nice, but who in high school today would care about areas & perimeters of rectangles? Perhaps 150 years ago, farmers would worry about acreage and fence lengths, but today?? At 03:10 AM 8/1/2012, Adam P. Goucher wrote:
I can easily come up with elementary applications of square roots, but are there any (many?) elementary/high school applications of the quadratic formula?
Find the dimensions of the rectangle with area A and perimeter P.
Solution: Solve x^2 - (P/2)x + A = 0.
This generalises to an elementary application of Cardano's formula, namely finding the dimensions of the cuboid with volume V, surface area S and total edge length L: x^3 - (L/4)x^2 + (S/2)x - V = 0.
Sincerely,
Adam P. Goucher