Question 670562
Find the volume of cylinder of a height 4cm whose total surface area is 484sqcm
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SA of a cylinder including top and bottom is
{{{SA = 2*pi*r*h + 2*pi*r^2}}}
{{{484 = 2*pi*r*4 + 2*pi*r^2}}}
{{{484 = 8*pi*r + 2*pi*r^2}}}
{{{2*pi*r^2 + 8pi*r - 484 = 0}}}
{{{pi*r^2 + 4pi*r - 242 = 0}}}
{{{r^2 + 4r - 242/pi = 0}}}
*[invoke solve_quadratic_equation 1,4,-242/pi]
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Ignore the -11 solution.
r = 7 (very close to 7)
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{{{Vol = pi*r^2*h = 196pi}}} cc
Vol =~ 616 cc