
Answer:
12.0 tablet computers/month
Step-by-step explanation:
The average price of the tablet 25 months from now will be:

Next, we determine the rate at which the quantity demanded changes with respect to time.
Using Chain Rule (and a calculator)

![\dfrac{dx}{dp}= \dfrac{d}{dp}\left[{ \dfrac { 100 } { 9 } \sqrt { 810,000 - p ^ { 2 } } }\right] =-\dfrac{100}{9}p(810,000-p^2)^{-1/2}](https://tex.z-dn.net/?f=%5Cdfrac%7Bdx%7D%7Bdp%7D%3D%20%5Cdfrac%7Bd%7D%7Bdp%7D%5Cleft%5B%7B%20%5Cdfrac%20%7B%20100%20%7D%20%7B%209%20%7D%20%5Csqrt%20%7B%20810%2C000%20-%20p%20%5E%20%7B%202%20%7D%20%7D%20%7D%5Cright%5D%20%3D-%5Cdfrac%7B100%7D%7B9%7Dp%28810%2C000-p%5E2%29%5E%7B-1%2F2%7D)
![\dfrac{dp}{dt}=\dfrac{d}{dt}\left[\dfrac { 400 } { 1 + \dfrac { 1 } { 8 } \sqrt { t } } + 200 \right]=-25\left[1 + \dfrac { 1 } { 8 } \sqrt { t } \right]^{-2}t^{-1/2}](https://tex.z-dn.net/?f=%5Cdfrac%7Bdp%7D%7Bdt%7D%3D%5Cdfrac%7Bd%7D%7Bdt%7D%5Cleft%5B%5Cdfrac%20%7B%20400%20%7D%20%7B%201%20%2B%20%5Cdfrac%20%7B%201%20%7D%20%7B%208%20%7D%20%5Csqrt%20%7B%20t%20%7D%20%7D%20%2B%20200%20%5Cright%5D%3D-25%5Cleft%5B1%20%2B%20%5Cdfrac%20%7B%201%20%7D%20%7B%208%20%7D%20%5Csqrt%20%7B%20t%20%7D%20%5Cright%5D%5E%7B-2%7Dt%5E%7B-1%2F2%7D)
Therefore:
![\dfrac{dx}{dt}= \left[-\dfrac{100}{9}p(810,000-p^2)^{-1/2}\right]\left[-25\left[1 + \dfrac { 1 } { 8 } \sqrt { t } \right]^{-2}t^{-1/2}\right]](https://tex.z-dn.net/?f=%5Cdfrac%7Bdx%7D%7Bdt%7D%3D%20%5Cleft%5B-%5Cdfrac%7B100%7D%7B9%7Dp%28810%2C000-p%5E2%29%5E%7B-1%2F2%7D%5Cright%5D%5Cleft%5B-25%5Cleft%5B1%20%2B%20%5Cdfrac%20%7B%201%20%7D%20%7B%208%20%7D%20%5Csqrt%20%7B%20t%20%7D%20%5Cright%5D%5E%7B-2%7Dt%5E%7B-1%2F2%7D%5Cright%5D)
Recall that at t=25, 
Therefore:
![\dfrac{dx}{dt}(25)= \left[-\dfrac{100}{9}\times 446.15(810,000-446.15^2)^{-1/2}\right]\left[-25\left[1 + \dfrac { 1 } { 8 } \sqrt {25} \right]^{-2}25^{-1/2}\right]\\=12.009](https://tex.z-dn.net/?f=%5Cdfrac%7Bdx%7D%7Bdt%7D%2825%29%3D%20%5Cleft%5B-%5Cdfrac%7B100%7D%7B9%7D%5Ctimes%20446.15%28810%2C000-446.15%5E2%29%5E%7B-1%2F2%7D%5Cright%5D%5Cleft%5B-25%5Cleft%5B1%20%2B%20%5Cdfrac%20%7B%201%20%7D%20%7B%208%20%7D%20%5Csqrt%20%7B25%7D%20%5Cright%5D%5E%7B-2%7D25%5E%7B-1%2F2%7D%5Cright%5D%5C%5C%3D12.009)
The quantity demanded per month of the tablet computers will be changing at a rate of 12 tablet computers/month correct to 1 decimal place.
Answer:
-0.25
Step-by-step explanation:
-8= 2/x
multiply both sides by x -> -8x =2
divide both sides by -8 -> x=2/-8
Ans= -1/4 = -0.25
To get 1/10 -> 1000/10 =100
and 1% of 100 -> 100/100 = 1 or 1%
100 for question 1
1 for q2
Answer:
4 cm
Step-by-step explanation:
The equation of a parabola with its vertex at the origin can be written as ...
y = 1/(4p)x^2
The problem statement tells us that one point on the parabola is (x, y) = (12, 9). We can put these values into the equation and solve for p, the distance from the focus to the vertex.
9 = 1/(4p)(12^2)
9×4/144 = 1/p = 1/4 . . . . . . . . multiply by the inverse of the coefficient of 1/p
Then p = 4, and the bulb is 4 cm from the vertex.
The area of the triangle is 52.5 ft squared.