got this question:

Pressure P and V are related by c . V cubed = c, where c is a constant.

Determine the approximate % change in c when p is increased by 3% and v is decreased by 1.2%

suggested answer:

( P = 1 ) x (V = 1 ) cubed = C (which is 100%)

Therefore (( P + 3%) x (1 - 1.2%)) Cubed = Cn

(1.03 x 0.988) Cubed = 1.053

then you would take Cn from C to get the aproximate % change.

is this right??