The demand function for a certain item is
x = p^{2}e^{-(p+7)}
Use interval notation to indicate the range of prices corresponding to elastic, inelastic, and unitary

** NOTE: **
When using interval notation in WeBWorK, remember
that:

You use 'I' for

And use 'U' for the union symbol.

a) The range of prices for elastic is

b) The range of prices for inelastic is

a) The prices for unitary is

You can earn partial credit on this problem.