Dr /dt = 7
A = pi r^2
dA / dr = 2pir
dA/dt = dA/dr * dr/dt = 2pir * 7 = 14pir
when r = 12 rate of change of the area = 14*pi*12 = 168pi
= 527.79 cm^2 / minute to nearest hundredth
If you mean to the nearest HUNDREDTH the answer is 14.60.
Answer:
x = √21.
Step-by-step explanation:
Triangles ADB and BCD are similar.
So their corresponding sides are in the same ratio:
x / 7 = 3 / x
x^2 = 21
x = √21.