
William W. answered 11/07/23
Top ACT Math Prep Tutor
If 6 is a zero, then (x - 6) is a factor of the polynomial. Since it has a multiplicity of 2, then (x - 6)2 is a factor.
If 2 is a zero, then (x - 2) is a factor.
If 4 - i is a zero, there will ALWAYS be a conjugate zero that goes with it, therefore 4 + i will also be a zero. And, if 4 - i is a zero, then (x - (4 - i)) is a factor and if 4 + i is a zero, then (x - (4 + i)) is a factor.
So the polynomial can be y = (x - 6)2(x - 2)(x - (4 - i))(x - (4 + i)) but we are told the leading coefficient is 6 therefore it must be y = 6(x - 6)2(x - 2)(x - (4 - i))(x - (4 + i)) or y = 6(x - 6)2(x - 2)(x - 4 + i)(x - 4 - i)
We can multiply the last 2 terms together to get a better appearing result.
results in x2 - 8x + 16 - i2 but since i2 = -1 then it becomes: x2 - 8x + 16 - -1 = x2 - 8x + 17
So the polynomial (in factored form) is y = 6(x - 6)2(x - 2)(x2 - 8x + 17)
You can multiply it out further if it is required in the same way as above.