I think that answer should be right. Since it is isosceles the base angles will be the same and the top angle is an angle bisector which means that the angle split on top has even splits. Since no other side lengths- or any lengths at that matter- are give, it is safe to assume that y=4.

4 0

3 years ago

The radius of a right circular cone is increasing at a rate of 1.5 in/s while its height is decreasing at a rate of 2.1 in/s. At

givi [52]

Answer:

The volume of the cone is changing at a rate of approximately 8670.796 cubic inches per second.

Step-by-step explanation:

Geometrically speaking, the volume of the right circular cone ( $V$ ), in cubic inches, is defined by the following formula:

$V = \frac{1}{3}\cdot \pi \cdot r^{2}\cdot h$ (1)

Where:

$r$ - Radius, in inches.

$h$ - Height, in inches.

Then, we derive an expression for the rate of change of the volume ( $\dot V$ ), in cubic inches per second, by derivatives:

$\dot V = \frac{1}{3}\cdot \pi \cdot (2\cdot r\cdot h \cdot \dot r + r^{2}\cdot \dot h)$ (2)

Where:

$\dot r$ - Rate of change of the radius, in inches per second.

$\dot h$ - Rate of change of the height, in inches per second.

If we know that $r = 120\,in$ , $\dot r = 1.5\,\frac{in}{s}$ , $h = 107\,in$ and $\dot h = -2.1\,\frac{in}{s}$ , then the rate of change of the volume is: