Given a quadratic equation in the form y = ax2 +bx +c , and four choices of graphs representing that equation, how can you tell which choices could be eliminated right away by looking at the equation and looking at the graphs and doing some minimal calculations and not actually plotting any of the points?

Answer 1

How can we answer without looking at the four choices of graphs?

See the following in regards to graphing quadratic functions.

http://www.purplemath.com/modules/grphquad2.htm

Answer 2

The graph of this equation will be which conic section?(x-5)^2+y^2=64