 Hi everyone, let's take a look at an example of a find the constant problem in which we're given the fact that we know there's a relative extrema present and we need to figure out missing values of a and b in the function. So in this case we have a quadratic x squared plus ax plus b and we are told there's a relative maximum at the point 6 comma negative 5. Well, because we know it's a maximum, it has to be true that x equals 6 is going to be a critical number because we know that if there is a relative extrema, maximum present, then that x value which it occurs should have been a critical number. So it's sort of backward thinking. So because we know it's a critical number, it must have come from the fact that the derivative there equals 0. So let's go ahead and find our derivative. That's simply going to be 2x plus a and we know that if we were to take that derivative and substitute that critical value of 6 in, so we'd have 2 times 6 plus a, remember that's supposed to be equaling 0 because critical numbers, remember, occur where your derivative equals 0 or your derivative does not exist. Now this is a polynomial function so there will not be any place that the derivative does not exist. So we get out of this that a equals negative 12. So there's one of the values right there that we need to know. So to find the other value we can go back to the original function on which we knew the ordered pair. We know the y value was negative 5. So now that we know that what a is and we know the x value has to be positive 6, that can enable us to find b. So if you go ahead and solve that out, I'll let you do the number crunching. You should find that b is 31. So there's the other value you need. Were this to occur on the AP exam as a multiple choice question, most likely you would be asked to find the sum of a and b. That's typically how they're going to word them on the multiple choice exam problems. But otherwise this hopefully gives you a good idea of how you can use what we've learned about finding relative extrema and intervals on which a function is increasing and decreasing to find missing values out of a function.