Quadratics — Quiz 3

Questions in this quiz (8)

1. Which of these is a quadratic equation with solutions $$\frac{4}{7}$$ and $$\frac{3}{5}$$?

   • $$35x^2 - 41x + 12 = 0$$
   • $$35x^2 - 38x + 12 = 0$$
   • $$35x^2 - 37x + 12 = 0$$
   • $$35x^2 - 39x + 12 = 0$$

2. What are the coordinates of the vertex of the quadratic function: $$y=x^2+6x+5$$

   • $$(-3,-4)$$
   • $$(3,4)$$
   • $$(3,-4)$$
   • $$(-3,-5)$$

3. Solve the equation: $$\frac{x^2}{4}-3x=-8$$

   • $$x=8$$ , $$x=4$$
   • $$x=-8$$ , $$x=-4$$
   • $$x=-8$$ , $$x=4$$
   • $$x=8$$ , $$x=-4$$

4. In the standard $$(x,y)$$ coordinate plane, the graph of $$y=x^2+px+12$$ crosses the $$x$$-axis at only one point. What does $$p$$ equal?

   • $$4\sqrt{3}$$
   • $$8\sqrt{7}$$
   • $$2\sqrt{6}$$
   • $$2\sqrt{5}$$

5. The height $$h(t)$$ of a ball thrown upward is given by the function:$$h(t)=-2+0.5t+0.3t^2$$where $$h(t)$$ is the height in meters and $$t$$ is the time in seconds. At what time does the ball reach the ground $$h(t)=0$$?

   • $$1.88$$
   • $$1.55$$
   • $$1.25$$
   • $$2.55$$

6. A school auditorium has $$280$$ seats, which are arranged in rows. The number of seats in each row is $$6$$ less than the number of rows. How many rows of seats are there in the auditorium?

   • $$18$$
   • $$15$$
   • $$20$$
   • $$13$$

7. A quadratic function passes through the point $$(6,-20)$$ and has x-intercepts at $$-4$$ and $$8$$. What is the vertex of the parabola?

   • $$(36,20)$$
   • $$(2,-36)$$
   • $$(4,72)$$
   • $$(4,-72)$$

8. Solve the equation by using the formula:$$2x^2+\sqrt{5}x-5=0$$

   • $${-\sqrt{2}, \sqrt{2}}$$
   • $${-5,-\sqrt{2}}$$
   • $${\frac{\sqrt{5}}{2},-\sqrt{5}}$$
   • $${-5,2}$$