Question

Which among the following is the correct graphical representation of $y=-x^2+4x+1$ ?

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

Since the sign of $x^2$ is negative, it will be a parabola opened towards negative y-axis. For the vertex part of it, we can write the given expression as
$y=-(x^2-4x-1)$
$=-(x^2-4x+4-5)$
$\Rightarrow y-5=(x-2{)}^2$
From this, we can say the vertex of the parabola is $(2,5)$