Given:
The equation of a quadratic function is:
[tex]H(x)=-x^2+10x-11[/tex]
To find:
The equation of the axis of symmetry for the given function.
Solution:
If a quadratic function is [tex]f(x)=ax^2+bx+c[/tex], then the equation of the axis of symmetry is:
[tex]x=-\dfrac{b}{2a}[/tex] ...(i)
We have,
[tex]H(x)=-x^2+10x-11[/tex]
Here, [tex]a=-1,b=10,c=-11[/tex]. So, the equation of axis of symmetry by using (i), is
[tex]x=-\dfrac{10}{2(-1)}[/tex]
[tex]x=-\dfrac{10}{-2}[/tex]
[tex]x=5[/tex]
Therefore, the correct option is C.
