Question

At what rate is the diagonal of a cube increasing if its edges are increasing at a rate of 2 cm/s?

Answer 1

not a great sketch... hope it makes sense...

Answer 2

first find this side in terms of s:

Answer 3

then use it to find this side (which is the diagonal of the cube)

Answer 4

if you can find an expression for the diagonal of a cube in your text book, you can just use that ... either way, let me know what you get... and we'll continue from there