Answer:
d = 4
Step-by-step explanation:
Given f varies inversely as d² then the equation relating them is
f = [tex]\frac{k}{d^2}[/tex] ← k is the constant of variation
To find k use the condition when d = 2, f = 6 , then
6 = [tex]\frac{k}{2^2}[/tex] = [tex]\frac{k}{4}[/tex] ( multiply both sides by 4 )
24 = k
f = [tex]\frac{24}{d^2}[/tex] ← equation of variation
When f = 1.5 , then
1.5 = [tex]\frac{24}{d^2}[/tex] ( multiply both sides by d² )
1.5d² = 24 ( divide both sides by 1.5 )
d² = 16 ( take the square root of both sides )
d = [tex]\sqrt{16}[/tex] = 4