Question

If the x+1 is the zero of the polynomial px^3+2x^2+5x+4 then find p of cubic polynomial?

Answer 1

Answer: x+1=0

x= -1

px^3+2x^2+5x+4 = 0

= p(-1)^3+2(-1)^2+5(-1)+4 = 0

= p(-1) + 2(1) + (-5) + 4 = 0

= -p + 2 - 5 + 4 = 0

= -p +1 = 0

= 1 = p

Therefore, p of this cubic polynomial is equal to 1.