What is the value of c such that x^2-11x+c is a perfect-square trinomial?

A perfect-square trinomial is a trinomial that can be factored into a binomial squared form.

For a quadratic trinomial ax^2 + bx + c to be a perfect-square trinomial, the coefficient of x should be equal to twice the square root of c.

In this case, we have the trinomial x^2 - 11x + c.

The coefficient of x is -11, so it must be equal to 2 times the square root of c: -11 = 2√c.

To solve for c, we can isolate the square root term:

√c = -11/2

Squaring both sides to eliminate the square root, we have:

c = (-11/2)^2

c = 121/4

Therefore, the value of c such that x^2 - 11x + c is a perfect-square trinomial is 121/4.