the volume of an oblique cone with equal diameter and height is 18\pi cm^3. find the height and radius.

I don't get how to do this

the volume of an oblique cone with equal diameter and height is 18pi cm3 find the height and radiusI dont get how to do this class=

Respuesta :

gmany

The formula of a volume of a cone:

[tex]V=\dfrac{1}{3}\pi r^2h[/tex]

We have:

[tex]2r=x\to r=\dfrac{x}{2}\\\\h=x\\\\V=18\pi\ cm^3[/tex]

substitute:

[tex] \dfrac{1}{3}\pi\left(\dfrac{x}{2}\right)^2\cdot x=18\pi\ \ \ \ |:\pi\\\\\dfrac{1}{3}\cdot\dfrac{x^2}{4}\cdot x=18\\\\\dfrac{x^3}{12}=18\ \ \ \ |\cdot12\\\\x^3=216\to x=\sqrt[3]{216}\\\\x=6\ cm [/tex]

[tex]h=x\to h=6\ cm\\\\r=\dfrac{x}{2}\to r=\dfrac{6}{2}=3\ cm[/tex]

Answer:

height = 6 cm

radius = 3 cm