You can’t have a smallest dimension of 4, because then the product of
the other two dimensions would have to be 8, and you can’t make a
product of 8 out of two integers greater than or equal to 4. So the five
possibilities listed above are the only possibilities.47 . A
Re-express the equation in standard form:
Then use the quadratic formula:This expression will be real as long as what’s under the radical is
nonnegative:48 . A
First put the inequality into standard form: