Geometry solve for X

For f(x)=1/x^2-3

Find  

A) f(3)

B) f(2-h)

If f(x)=1/x^2-3, then f(3) = 1 / 3^2 - 3.  The exponentiation here must be carried out first:  f(3) = 1/9 - 3.  Then f(3) = 1/9 - 27/9 = -26/9

If f(x)=1/x^2-3, then f(2-h) = 1 / [2-h]^2 - 3.  This result may be left as is or expanded.  In expanded form, we have:

                     1

f(2-h) = - 3

              4-4h +h^2