Question

q varies jointly with v and s. When v=2 and s=3, q=24. Find the constant of variation, then write an equation to describe the relationship then use your equation to find q when v=4 and s=2.

Answer 1

Do you know what joint variation means?

Answer 2

yes

Answer 3

q varies jointly with v and s

\[q\propto vs\\
q=kvs\]

Answer 4

every z is the same # times x & y. (z varies jointyly with x & y. Model = kxy

Answer 5

Right. So, what is \(k\) in this case?

\[q = k * v *s\]\[24 = k*2*3\]\[k =\]

Then use that value of \(k\) to evaluate \[q = k * v * s\] with \(v=4,\, s=2\)

Answer 6

You can also shortcut the latter computation by noticing that the first time around you have k*2*3 and the second time you have k*4*2, so the new value of q will simply be the old value of q*4/3

Answer 7

okay, thank you :-)