Until now we got the quadratic equation which is 
there is a sign like >,<,>=,<= instead of =, it really confused other people. Although, If you know how to graph properly and make the x and y values perfect, it is all done. For example, $ax^2 + bx + c $ < 0, that means y value of this graph is under 0. There could be another number instead of 0 which follows the same rules as y values is all under that number. On the other hand, if the sign is >, or >= that means the y intercept of that graph is over that
number or same/over the number. We can easily see the result by just checking the sing below.