Taking
and differentiating both sides with respect to
yields
![\dfrac{\mathrm d}{\mathrm dx}\bigg[3x^2+y^2\bigg]=\dfrac{\mathrm d}{\mathrm dx}\bigg[7\bigg]\implies 6x+2y\dfrac{\mathrm dy}{\mathrm dx}=0](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Cmathrm%20d%7D%7B%5Cmathrm%20dx%7D%5Cbigg%5B3x%5E2%2By%5E2%5Cbigg%5D%3D%5Cdfrac%7B%5Cmathrm%20d%7D%7B%5Cmathrm%20dx%7D%5Cbigg%5B7%5Cbigg%5D%5Cimplies%206x%2B2y%5Cdfrac%7B%5Cmathrm%20dy%7D%7B%5Cmathrm%20dx%7D%3D0)
Solving for the first derivative, we have
Differentiating again gives
![\dfrac{\mathrm d}{\mathrm dx}\bigg[6x+2y\dfrac{\mathrm dy}{\mathrm dx}\bigg]=\dfrac{\mathrm d}{\mathrm dx}\bigg[0\bigg]\implies 6+2\left(\dfrac{\mathrm dy}{\mathrm dx}\right)^2+2y\dfrac{\mathrm d^2y}{\mathrm dx^2}=0](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Cmathrm%20d%7D%7B%5Cmathrm%20dx%7D%5Cbigg%5B6x%2B2y%5Cdfrac%7B%5Cmathrm%20dy%7D%7B%5Cmathrm%20dx%7D%5Cbigg%5D%3D%5Cdfrac%7B%5Cmathrm%20d%7D%7B%5Cmathrm%20dx%7D%5Cbigg%5B0%5Cbigg%5D%5Cimplies%206%2B2%5Cleft%28%5Cdfrac%7B%5Cmathrm%20dy%7D%7B%5Cmathrm%20dx%7D%5Cright%29%5E2%2B2y%5Cdfrac%7B%5Cmathrm%20d%5E2y%7D%7B%5Cmathrm%20dx%5E2%7D%3D0)
Solving for the second derivative, we have
Now, when
and
, we have
To solve this problem you will need to use the cross product method:
1/16 of an hour → write 1 card
3/4 of an hour → write X cards
(3/4) ÷ (1/16) = X
0.75 ÷ 0.0625 = X
12 = X
Joey can write 12 Thank you cards in 3/4 of an hour.
There you go! I really hope this helped, if there's anything just let me know! :)
Answer:
Step-by-step explanation:
Answer:
the answer is c)SAS
Step-by-step explanation:
as the sides are already given and and both angles will be equal as vertically opposite angles (VOA)are always equal.
The answer is b. 11.
You can find this by multiplying the two parenthesis together. In order to do this, you can use a multiplying process known as FOIL (First, Outer, Inner, Last), where you multiply parts of the parenthesis in this order to make sure you do so properly.
First Numbers:
2x * x = 2x^2
Outer Numbers:
2x * 6 = 12x
Inner Numbers:
-1 * x = -1x
Last Numbers:
-1*6 = -6
Now place them all in that order and simplify.
2x^2 + 12x - x - 6 ---> simplify x terms
2x^2 + 11x - 6
Since the middle term (the one with the x value) has a coefficient of 11, that gives us a b value of 11.
