A cone-shaped lamp has an inner volume of 48π cubic centimeters and a height 1 centimeter more than twice its radius r. What are the possible values of the r? Which is a reasonable value?
2 answers
Can you help please
since v = 1/3 πr^2h, we have
π/3 r^2(2r+1) = 48π
r^2(2r+1) = 144
since 144 = 16*9, r=4 works fine.
Divide by (r-4) to make a quadratic, and there are no other real solutions.
π/3 r^2(2r+1) = 48π
r^2(2r+1) = 144
since 144 = 16*9, r=4 works fine.
Divide by (r-4) to make a quadratic, and there are no other real solutions.
1 answer