Question

Find the value D(−1), where D is defined below.D(x)=x2−2x−1

Answer 1

Given:

The expression is given as,

$D(x)=x^2-2x-1$

The objective is to find D(-1).

Explanation:

On substituting the value of x = -1 in the given equation,

$D(-1)=(-1)^2-2(-1)-1_{}$

On further solving the above equation,

$\begin{gathered} D(-1)=1+2-1 \\ =3-1 \\ =2 \end{gathered}$

Hence, the value of D(-1) is 2.