1, Suppose z varies directly with z and inversely with the square of y. If z = 12 when I = 3 and y what is z when 3 = 8 and y = 8? 2 = Question Help: D Video

1 Suppose z varies directly with z and inversely with the square of y If z 12 when I 3 and y what is z when 3 8 and y 8 2 Question Help D Video class=

Respuesta :

z = 1/2

Explanation:[tex]\begin{gathered} z\text{ }\alpha\text{ x} \\ z\text{ }\alpha\text{ 1/}y^2 \end{gathered}[/tex]

combining both:

[tex]\begin{gathered} z\text{ }\alpha x/y^2 \\ z\text{ = }\frac{kx}{y^2} \\ \text{where k = constant of proportionality} \\ \text{and }\alpha\text{ means varies } \end{gathered}[/tex]

when z = 12, x = 3, y = 1

Inserting the values, we get k:

[tex]\begin{gathered} 12\text{ = }\frac{k(3)}{1^2} \\ 12\text{= }\frac{3k}{1} \\ 12\text{ = 3k} \\ k\text{ = 12/3} \\ k\text{ = 4} \end{gathered}[/tex][tex]z\text{ = }\frac{4x}{y^2}\text{ (relationship connnecting the variables)}[/tex]

when x = 8, y = 8, z= ?

[tex]\begin{gathered} \text{Inserting into the relationship:} \\ z\text{ = }\frac{4(8)}{8^2} \\ z\text{ = }\frac{32}{64} \\ z\text{ = 1/2} \end{gathered}[/tex]