15) 5/8
16)21.16 meters
17)C
<span>(5, 0) and (5, -2) are the two points that are on the line x=5. This is some basic math.
Hope it helps :)</span>
<span>A = pi r^2
dA/dt = 2 pi r dr/dt
dr/dt = 15 cm/s
a) r = 30
dA/dt = 2 pi (30) (15) = 900 pi cm^2/s
b)
A = 9 = pi r^2
r = 3 / sqrt(pi)
dA/dt = 2 pi( 3/sqrt(pi)) (15) = 90 sqrt(pi) cm^2/s</span><span>
</span>
just a guess so don't take seriously
No
