Quadratic graphs (parabola)

Move the sliders to change the coefficents a, b and c. In [math]y=ax^2+bx+c[/math].

[math][/math]Write all your answers in your exercise book. 1. What effect does changing 'c' have on the graph? Write the equation of 5 parabolas with a [math]y[/math] intercept of 3. 2. Change 'a' describe what efect this has on the graph. What does happens when 'a' is negative? 3. Keep coeffcient a=1 and alter coefficent b (use a table to record your results). a) How does altering b effect the [math]x[/math] coordinate of the vertex of the graph? b) Can you predict what the[math]x[/math] coordinate of the vertex of [math]y=x^2+18x+3[/math] will be? c) Can you find a rule that would work for every case? Does your rule work when a = 2? 4. Use the graph to decide if you could solve this equation [math]x^2+2x+8=0[/math]. If you can solve it find the values of [math]x[/math]. If you can't solve it why not? 5. Use your graph to decide which of these equations are correct. Alter each incorrect equation to make it true. a) [math]x^2-5x+2=0 [/math] b) [math]2x^2-4x+2=0[/math] c) [math]0.5x^2+x-1=0[/math] d) [math]x^2+4x-5=0[/math]