Answer:
a = 12
Step-by-step explanation:
Given that a is inversely proportional to b then the equation relating them is
a = [tex]\frac{k}{b}[/tex] ← k is the comstant of proportion
To find k use the condition when a = 4, b = 36, then
4 = [tex]\frac{k}{36}[/tex] ( multiply both sides by 36 )
144 = k
a = [tex]\frac{144}{b}[/tex] ← equation of proportion
When b = a , then
a = [tex]\frac{144}{a}[/tex] ( multiply both sides by a )
a² = 144 ( take square root of both sides )
a = ± [tex]\sqrt{144}[/tex] = ± 12
However a is a positive number, thus a = 12