Suppose xy=4 and dy/dt=-2. Find dx/dt when x=-3

2 answers:

4 0

We are given with the expression xy = 4. The first derivative of the x is dx/dt while that of y is dy/dt. in this case using the multiplication rule of differentiation and that of constants, x dy/dt + y dx/dt = 0. when x= -3, y should be -4/3. Hence when dy/dt = -2, -3(-2) -4/3 *dx/dt = 0. dx/dt is equal to 9/2.

nirvana33 [79]3 years ago

3 0

Dy/dx = dy/dt * dt/dx

xy = 4

y + x(dy/dx) = 0 by implicit differentiation.

x(dy/dx) = -y

dy/dx = -y/x

<span>dy/dx = dy/dt * dt/dx dy/dt = -2
</span>
<span>-y/x = -2 * dt/dx
</span>
y/(2x) = dt/dx

dt/dx = y/(2x)

dx/dt = 2x/y

When x = -3, xy = 4, y = 4/x = 4/-3 = -4/3

dx/dt = 2*-3/(-4/3) = -6 *-3/4 = 18/4 = 9/2 = 4.5

dx/dt = 4.5

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Degger [83]

Answer:

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MAVERICK [17]

Answer:

see attached

Step-by-step explanation:

Dilation is the transformation that changes the size of something. When you choose ×110% on a copy machine, you are making all the dimensions in the copy equal to 1.1 times the dimensions of the original, for example. That is dilation by a factor of 1.1, or 110%.

Here, you're asked to dilate triangle ABC by a factor of 3. That means all of the dimensions on the dilated figure will be 3 times their length on the original.

The center of dilation is point P. That means all the distances from point P are multiplied by 3.

In the attached figure, a gray arrow has been drawn from point P to each of the points A, B, and C. Then two more arrows of the same length are drawn in the same direction. The total distance at the end of the 3 arrows is 3 times the original distance from point P. These are the points A', B', and C' you are asked to draw. Connecting these points gives the dilated triangle A'B'C'.

___

You could think of point P (the center of dilation) as having coordinates (0, 0). Then points A, B, and C would have coordinates A(-4, 0), B(0, -3), and C(-4, -3). To dilate these points by a factor of 3, multiply each coordinate value by 3: A'(-12, 0), B'(0, -9), C'(-12, -9). You will see that these are the coordinates of the vertices of the dilated triangle.