Question

If y varies inversely as the square ofx, and Y -

4
when x - 3, find y when x = 5.
63
a
c.
7
Y-
100
b
4
d.
175
125
a V(3) -
V-733 () - 4
Spa (5)
Please select the best answer from the choices provided
Ο Α
C B
C

Answer 1

When x = 5, y = 1.44

Explanation:

We know that when 'y' varies inversely with 'x', we get the equation

y ∝ 1/x

y = k/x

where 'k' is called the constant of proportionality

In our case, given that y varies inversely as the square of x.

so

y ∝ 1/x²

y = k/x²

When x = 3, y = 4, we need to find k

y = k/x²

k = yx²

k = 4(3)²

k = 36

so, the value of k = 36

Now, we need to find y when x = 5

so substitute k = 36, x = 5 in the equation

y = k/x²

y = 36 / (5)²

y = 36 / 25

y = 1.44

Therefore,

• when x = 5, y = 1.44