Answer:
A) - Quartic polynomial
- has four roots
- roots are; f(x) = (x + 5i)(x - 5i)(x + 2)(x - 2)
B) - Cubic polynomial
- has 3 roots
- roots are; f(x) = (x - 5)²(x + 5)
Step-by-step explanation:
A) f(x) = x⁴ + 21x² − 100
The highest power in this polynomial is 4 and thus, it is called a quartic polynomial. This means that it will have 4 roots.
Factorizing this polynomial gives;
f(x) = (x² + 25)(x² - 4)
Equating to zero, we can find the roots. Thus, the roots are;
x = 5i
x = -5i
x = 2
x = -2
Thus, the completely factorized polynomial is;
f(x) = (x + 5i)(x - 5i)(x + 2)(x - 2)
B) f(x) = x³ − 5x² − 25x + 125
The highest power in this polynomial is 3. It is therefore a cubic polynomial with 3 roots.
Factorizing this polynomial gives;
f(x) = (x² - 25)(x - 5)
Equating to zero and Factorizing gives;
x = 5
x = -5
x = 5
Thus, completely factorized with the roots is;
f(x) = (x - 5)²(x + 5)
