What is a quartic function with only the two real zeros give
What is a quartic function with only the two real zeros given?
x = -4 and x = -1
A. y = x4 + 5x3 + 5x2 + 5x + 4
B. y = x4 - 5x3 - 5x2 - 5x - 4
C. y = -x4 + 5x3 + 5x2 + 5x + 4
D. y = x4 + 5x3 + 5x2 + 5x - 5
| A. y = x4 + 5x3 + 5x2 + 5x + 4 | |
| B. y = x4 - 5x3 - 5x2 - 5x - 4 | |
| C. y = -x4 + 5x3 + 5x2 + 5x + 4 | |
| D. y = x4 + 5x3 + 5x2 + 5x - 5 |
Solution
x = -4 and x = -1
quartic equation with given zeros is
y = x^4 + 5x^3 + 5x^2 + 5x + 4
since plugging x = -4 and x = -1 makes the equation equal to zero
(-4)^4 + 5(-4)^3 + 5(-4)^2 + 5(-4) + 4 = 0
(-1)^4 + 5(-1)^3 + 5(-1)^2 + 5(-1) + 4 = 0
hence x =-4 and x = -1 are its zeros
