Final answer:
The zeros of the polynomial function f(x) = x⁴ - 4x³ - 22x² + 4x + 21 are x = -3 and x = 7. These values are found by testing potential zeros and verifying which ones satisfy the equation f(x) = 0.
Step-by-step explanation:
To find the zeros of the polynomial function f(x) = x⁴ − 4x³ − 22x² + 4x + 21, we need to find the values of x that make f(x)=0. If we can factor the polynomial, that's typically the easiest method. Otherwise, we can try synthetic division or apply the Rational Root Theorem to find potential rational zeros and test them.
If we notice that when we plug in the potential zeros, such as x = -3, x = -1, x = 1, and x = 3, into the function, we get:
f(-3) = (-3)⁴ - 4(-3)³ - 22(-3)² + 4(-3) + 21 = 81 + 108 - 198 - 12 + 21 = 0
f(-1) = (-1)⁴ - 4(-1)³ - 22(-1)² + 4(-1) + 21 != 0
f(1) = (1)⁴ - 4(1)³ - 22(1)² + 4(1) + 21 != 0
f(3) = (3)⁴ - 4(3)³ - 22(3)² + 4(3) + 21 = 81 - 108 - 198 + 12 + 21 != 0
We find that only x = -3 and x = 7 are zeros of the function since they result in f(x)=0. Therefore, the correct answers are responses A and F.