# Value of the constant

• Jun 29th 2006, 09:23 AM
kwtolley
Value of the constant
Express the following statement as a formula with the value of the constant of proportionality determined with the given conditions: w variers directly as x and inversely as the square of y. If x=15 and y=5, then w=36. Ok my anwser is w=36 x/y^2 is this right I don't think so. Thanks for any help given.
• Jun 29th 2006, 01:37 PM
Soroban
Hello, kwtolley!

Quote:

Express the following statement as a formula with the value of the constant of proportionality
determined with the given conditions:

$w$ variers directly as $x$ and inversely as the square of $y$.
If $x=15$ and $y=5$, then $w=36$.

Ok, my answer is: $w = \frac{36x}{y^2}$ . . . Is this right? . . . sorry, no
It looks like you started correctly: . $w \:= \:\frac{kx}{y^2}$

We're told that: . $x = 15,\;y=5,\;w = 36$

Plug them in: . $36 = \frac{k\cdot15}{5^2}\quad\Rightarrow\quad k = 60$

Therefore: . $w \:=\:\frac{60x}{y^2}$
• Jul 2nd 2006, 08:10 AM
kwtolley
thank you note