A quadratic function is one of the form f(x) = ax2 + bx + c, where a, b, and c are numbers with a not equal to zero. The graph of a quadratic function is a curve called a parabola. ... A parabola intersects its axis of symmetry at a point called the vertex of the parabola. You know that two points determine a line.
The horizontal stretch is the correct answer. A period is the distance on the x-axis that it takes for the tangent or cotangent function to repeat itself. Stretching it out horizontally will lengthen that distance and therefore change the period.
