The expression b2 4ac is called the discriminant and in some books you will see it written with a Greek upper case Delta like this Delta b2 4ac. Visit the post for more. A Find the coordinates of the centre of C.
There are an infinite number of those points here are some examples.
A teacher code is provided by your teacher and gives you free access to their assignments. As D th 0 summing up each of the pieces to gain the full area gives us the formula. This is how the 1 2 comes about. The area of each division ends up yielding half the angle required to find such area.