Question

In the function y=f(x), y varies inversely with the square of x and when x=4, y=1/2. Find y when x=1.

Answer 1

ok so

y= 4/3x2

Y varies inversely with square of x means

y = k (1/x²) where k is the constant

plug in y =1/3 and x = - 2 in the above equation.

1/3=k (1/{-2}²)

1/3=k (1/4)

multiply with 4 to both sides.

4/3 =k

therefore,

y=4/3 (1/x²) = 4/3x²