Suppose that the radius of a circle increases at a constant rate of 0.25 cm/sec. When the radius of this circle is 16 cm, the area of the circle increases at a rate of

8πcm²/sec

Step-by-step explanation:

The radius of the circle increases at a rate of dr/dt = 0.25cm/sec

The radius of the circle r = 16cm

The area of the circle increases at a rate of dA/dt = ?

Area of a circle = πr²

We take the derivative with respect to t

dA/dt = 2πrdr/dt

dA/dt = 2 π (16)(0.25)

dA/dt = 8πcm²/sec

Thank you!!!

8pi cm^2/sec

Step-by-step explanation:

took the unit test, also give other person brainliest, their answer was REALLY good.

if gloria has "carry over" minutes, (that is, any minutes paid for but not used in a month can be applied to her payment for minutes in the next month,) her total usage for the three months is: total minutes = 320 + 243 + 489 = 1052 minutes number of 200 minute blocks = 1052/200 = 5 r52 (that is 5 with a remainder of 52) rounding up the number of 200 minute blocks gives her usage for the three months as 6 blocks. the cost for six blocks is 6 x $25 = $150 she also has 200 - 52 or 148 carry over minutes if gloria pays each month and unused minutes are lost, applying the rounding up procedure to each month gives: first month usage of 320 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 second month usage of 243 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 third month usage of 489 minutes rounds up to 3 blocks of 200 minutes for a payment of 3 x $25 = $75 total payments for the three months are $50 + $50 + $75 = $175 get the plan with carry over minutes!

its totaly b

your welcome btw