Given:
a varies jointly as b and c.
a=6 when b=2 and a=3.
To find:
The variation constant and the equation of variation.
Solution:
a varies jointly as b and c.
[tex]a\propto bc[/tex]
[tex]a=kbc[/tex] ...(i)
Where, k is the constant of proportionality.
a=6 when b=2 and a=3.
[tex]6=k(2)(3)[/tex]
[tex]6=6k[/tex]
[tex]\dfrac{6}{6}=k[/tex]
[tex]1=k[/tex]
The value of k is 1.
Putting k=1 in (i), we get
[tex]w=1xy[/tex]
[tex]w=xy[/tex]
Therefore, the variation constant is 1 and the equation of variation is [tex]w=xy[/tex].