Help Finding elasticity of demand!!
Find the elasticity of demand for each of the following demand functions. Ineach case determine how elasticity varies as price varies.
a) q = 30 - 2p , 0 < p < 15
b) q = p^-a , a > 0
c) q = 100 - 2p^2 , 0 < p < sqrt(20)
d) q = 1/ln(3p) , p>1/3
so (a) is pretty simple as it is linear, its -2, but i'm not sure how to calculate the other ones.
For example, (c) is a parabola, so how would i calculate overall elasticity of demand?
Help with b, c , or d is much appreciated.
thanks in advance