Final answer:
To find the value of p, use the quadratic formula and determine if it is positive or negative. Hence the correct answer is option A
Step-by-step explanation:
In order to find the value of p, we can use the quadratic formula. The quadratic formula can be used to find the solutions to any quadratic equation of the form ax^2 + bx + c = 0. By plugging in the values of a, b, and c from the equation into the formula, we can calculate the values of x.
Once we have the values of x, we can determine the value of p. If the value of p is positive, it means that the parabola opens upwards. If the value of p is negative, it means that the parabola opens downwards.
Therefore, the correct answer is A) By using the quadratic formula; Positive.