Question

if y is directly proportional to x³ and y = 108 when x = 3 then find an equation connecting x and y?​

Answer 1

If

y

is directly proportional to

x

2

then there is a constant

c

such that

y

=

c

⋅

x

2

If

y

=

36

,

x

=

3

is a solution to this equation

36

=

c

⋅

3

2

=

9

c

→

c

=

4

So the equation is

y

=

4

⋅

x

2