@kitkitbobit
What exactly are you having trouble with regarding the formula?
The quadratic formula is essentially to find the roots (also known as zeros) of a function. The roots of a function are where the function crosses the x-axis (essentially, they are x-intercepts). The quadratic formula will allow you to find these for a quadratic function (i.e. the degree of the polynomial is 2).
The form of a quadratic function is: ax^2 + bx + c, where a, b, c are real numbers. a cannot equal to 0.
Then, the quadratic formula is given by the formula: (-b +/- sqrt(b^2 - 4ac))/2a
- The +/- part refers to addition and subtraction. Once you simplify the formula, you will have two seperate equations. One with addition, and one with subtraction.
Plug in the values and solve. You will be given your zeros (i.e. your x-intercepts).
A little note: If you are dealing with word problems, where your x-axis is denoted by time, and you end up getting a negative root, you must disregard it as time cannot be negative.