A 4th degree polynomial will have at most 3 extreme values. Since the degree is even, there will be one global extreme, with possible multiplicity. The remainder, if any, will be local extremes that may be coincident with each other and/or the global extreme.
(The number of extremes corresponds to the degree of the derivative, which is 1 less than the degree of the polynomial.)
9514 1404 393
Answer:
(x, y) = (-1, -16) or (3, 0)
Step-by-step explanation:
Perhaps you want to solve the system of equations ...
Substituting the first expression for y into the second equation gives ...
x^2 +2x -15 -4x = -12
x^2 -2x -3 = 0 . . . . . . . . add 12
(x -3)(x +1) = 0 . . . . . . . factor
Solutions are the values of x that make the factors zero: x = 3, x = -1.
The corresponding values of y are ...
y = -12 +4x
y = -12 +4{-1, 3} = -12 +{-4, 12} = {-16, 0}
The solutions to the system are ...
(x, y) = (-1, -16) or (3, 0)
