The polynomial function [tex]$x^3 + ax^2 -1[/tex] will have -1 as a root at the value of
a = 2.
What is a polynomial function?
A polynomial function exists as a function that applies only non-negative integer powers or only positive integer exponents of a variable in an equation like the quadratic equation, cubic equation, etc.
Given: A root exists at a value of x such that the polynomial exists equivalent to zero.
Let, the polynomial equation be [tex]$x^3 + ax^2 -1[/tex]
then [tex]$\mathbf{f}(\mathbf{x})=\mathbf{x}^{3}+a \mathbf{x}^{2}-\mathbf{1}$[/tex]
Put, x = -1, then we get
[tex]$\mathbf{f}(-1)=(-1)^{3}+\mathrm{a}(-1)^{2}-1=0$[/tex]
f(-1) = a - 2 = 0
a = 2
Therefore, the value of a = 2.
To learn more about polynomial function
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