Question

Which among the following is the correct graphical representation of the quadratic polynomial $y=-x^2-2x+3?$

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

Since the coefficient of $x^2$ is negative the parabola will be downward opening parabola, i.e. ; opening towards negative y-axis.
We get the roots of the quadratic equation by putting $y=0$
$\Rightarrow y=-x^2-2x+3=0$
$\Rightarrow -x^2-3x+x+3=0$
$\Rightarrow -x(x+3)+1(x+3)=0$
$\Rightarrow (x+3)(-x+1)=0$
$\Rightarrow x=1,-3$
From this we can say that the graph will cut the x-axis at $1\&-3.$