Set 11: Quadratic Equations

Choice A is correct. Choice A is the correct answer. * Quadratic ($a < 0$): Parabola opening downward (Hill shape). Goes up, peaks, goes down. * Quadratic ($a > 0$): Parabola opening upward (Valley shape). Goes down, bottoms out, goes up. * Linear: Always goes up or always goes down. * Exponential: Always increases or always decreases. Choice B is incorrect because it goes down then up. Choice C is incorrect because it only goes up. Choice D is incorrect because it only goes up.