Question

What is the maximum height of any point on the curve $y=-x^2+6x-5$ above the $x-$axis?

• A. $4$
• B. $2$
• C. $6$
• D. $8$

Answer 1

The correct option is A $4$

$y=-x^2+6x-5$
$=4-(x-3{)}^2$
Now $(x-3{)}^2\ge 0$ for all real $x,$
Hence, the maximum value of $y$ (or $-x^2+6x-5$) is $4$, which is the height of the graph above $x-$axis.

Hence, option 'A' is correct.