How equation is formed

[fuofa]

Hi,

I am having trouble understanding how the equation pi R^4/4 becomes pi D^4/64. I know it calculates out all ok using those figures to get the same answer. I'm sure it's a simple explanation, but given in the first one that D=2R I don't see how we can arrive at the second equation. Help please!

 

[Otis]

the equation pi R^4/4

Hi. Technical Point: That is not an equation; it's an expression. All equations contain an equals sign. Cheers!

 

[fuofa]

Since D = 2R, then R = D/2

R^4 = (D/2)^4 = D^4 / 16
OK?

Yes! That explains it perfectly. Thank you ever so much.

 

[fuofa]

Since D = 2R, then R = D/2

R^4 = (D/2)^4 = D^4 / 16
OK?

Thats perfect, thank you. Very helpful.