If you have a quadratic equation of the form , then the two roots can be calculated using the coefficients of the quadratic trinomial thus:
In your case, the quadratic is in and the coefficients are , , and . Just plug in the numbers and do the arithmetic:
In this problem, the quantity under the radical, that is to say is less than zero. That means that your two roots will be a conjugate pair of complex roots of the form where is the imaginary number defined by
