Question

Q The cube root of x varies inversely as the square of y. If x 8 when y = 512 ​

Answer 1

Step-by-step explanation:

Write the english as maths:

y

∝

1

3

√

x

Change the variation to an equation by multiplying by a constant.

y

=

k

3

√

x

we need to find a value for

k

k

=

3

√

x

×

y

=

3

√

8

×

12

=

2

×

12

=

24

Replace

k

with

24

to obtain the equation

y

=

24

3

√

x

Now we can calculate y for any given x.

y

=

24

3

√

1

=

24

1

=

24