The ball's velocity will be represented by the derivative of its distance function:

Now find the times

for which this is equal to 30, i.e. solve

This has two solutions,

, but only one is positive and falls in the interval
![[0,3]](https://tex.z-dn.net/?f=%5B0%2C3%5D)
. So the velocity reaches 30 cm/s when

.
45 :)))))))))))))))))))))))))))))))
Answer:
t + f = 2000
let represent the amount invested at three percent; let f represent the amount invested at five percent. The total of these amounts is $20,000. The total of the interest earned by each amount is $800. Of course the interest earned is the amount multiplied by the interest rate.
Answer:
x = -8/b
Step-by-step explanation:
2bx – bx = -8
Combine like terms
bx = -8
Divide by b
bx/b = -8/b
x = -8/b