'L varies jointly as a and square root of b, and L = 72 when a = 8 and b = 9. Find L when a = 1/2 and b = 36?

1 Answer
Mar 14, 2017

L=6

Explanation:

As L varies jointly as a, we can say La

and square root of b means that Lb

and we can combine the two as Lab, which means

L=k×a×b, where k is a constant.

As L=72, when a=8 and b=9, it means

72=k×8×9=24k i.e. k=7224=3 and

L=3ab

Hence, when a=12 and b=36

L=2×12×36=2×12×6=6