A quadratic function is of form y = ax² + bx + c where a ≠ 0 and a, b, c are real number. Graph of quadratic functions are always a parabola either opening upwards or downwards.
To plot graph of any quadratic function, we need answers of these question
What is sign of ‘a’ or coefficient of x2 in quadratic function?
Whether the graph of quadratic function intersects with x-axis? And if it does at what point does it intersect?