Please help: perimeter of polygon ABCDEF

Given the relationship x2 + 3y2 =12, with y > 0 and dx, dt = 2 units/min., find the value of dy, dt at the instant y = 1 unit

matrenka [14]

$\bf x^2+3y^2=12\implies \stackrel{chain~rule}{2x\cfrac{dx}{dt}}+3 \stackrel{chain~rule}{\left(2y\cfrac{dy}{dt}\right)}=0
\\\\\\
2x\cfrac{dx}{dt}+6y\cfrac{dy}{dt}=0
\implies 
6y\cfrac{dy}{dt}=-2x\cfrac{dx}{dt}\implies \cfrac{dy}{dt}=\cfrac{-2x\frac{dx}{dt}}{
6y\frac{dy}{dt}}
\\\\\\
\boxed{\cfrac{dy}{dt}=-\cfrac{x\frac{dx}{dt}}{3y}}\\\\
-------------------------------$

$\bf \textit{now, when y = 1, what is \underline{x}?}\qquad x^2+3y^2=12\implies x^2+3(1)^2=12
\\\\\\
x^2=9\implies x=\sqrt{9}\implies x=3\\\\
-------------------------------\\\\
\begin{cases}
y=1\\
x=3\\
\frac{dx}{dt}=2
\end{cases}\implies \cfrac{dy}{dt}=-\cfrac{3\cdot 2}{3\cdot 1}\implies \cfrac{dy}{dt}=-2$

7 0

3 years ago

Please help <br> I will mark brainlist

Naya [18.7K]

Answer:

B x = sqrt(48)

Step-by-step explanation:

Half of the bottom side measures 4.

4^2 + x^2 = 8^2

16 + x^2 = 64

x^2 = 48

x = sqrt(48)

Answer: B x = sqrt(48)

4 0

3 years ago

...................................................................

Genrish500 [490]

Answer:

12 cm

Step-by-step explanation:

The Pythagorean Theorem is as follows:

$a^{2} +b^{2} =c^{2}$

A and B represent the side lengths (legs) and C represents the hypotenuse.

The length of one leg equals 5cm. (This can be represented by either a or b)

The hypotenuse equals 13 cm.

Plug these into the equation from above:

$a^{2} + (5^{2}) = (13^{2})$

Solve for the other leg:

$a^{2} + 25 = 169$ Square what's in the parentheses from above

$a^{2} = 144\\$ Subtract 25 from 169

$\sqrt{a^{2} } = \sqrt{144}$ Square root both sides

a = 12 cm

Thus, the length of the other leg is 12 cm.

Let's check our answer:

$12^{2} +5^{2} =13^{2}$ Square everything

144 + 25 = 169 Add

169 = 169

Because both sides are equal it means that 12 cm is the correct answer.

Hope this helps!!

3 0

2 years ago

Which expression is equal to 45 x 4-7: 4-27 4° 4-4 (45) (4-2) 45 : 4-9

horsena [70]

Answer: 173: -432° - 16196: -5

Step-by-step explanation: Simplify your expression and there is your answer.

4 0

3 years ago

Plzzz help me I don’t understand aTT ALL if I don’t do it I’ll get a 0 in my report card plz help

Digiron [165]

Answer:

hi there! i can help you out! i don't want you to get a zero on your report card!!

Step-by-step explanation:

so, on the x-axis, which is all the numbers through 1-10 and there are the patient's number. so for ex, the first question says patient 1 : 3 hours right??

so the hours are the y-axis and you can label them 2,4,6,8 because skip counting by twos are probably the easiest! so for the first question, you would line a dot up on top of 1 and go up and you see 2 and 4 right, cuz you just labeled it... do go between 2 and 4 which is 3 and place the dot there...

and keep doing the same things with other ones too...

another ex! so on the second question, it says patient 2 : 7 hours so place the dot on top of the 2 and go up untill you see 6 and 8 and place the dot beween them!

7 0

3 years ago

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