Which of the following is the graph of f(x) = x2 − 5x + 4?

Verified Answer :

I made a graph of the equation hope this helps.

View image rarrininger

Answer:

 refer attachment for the graph.

Step-by-step explanation:

Given: The equation \(f(x)=x^2-5x+4\)

We have to draw the the graph for the given equation.

Consider the given equation  \(f(x)=x^2-5x+4\)

The vertex of the parabola of the form  \(f(x)=ax^2+bx+c\) is given by \(x=-\frac{b}{2a}\)

Here, a = 1 , b = -5 and c = 4

Thus, vertex is

\(x_v=-\frac{\left(-5\right)}{2\cdot \:1}=\frac{5}{2}\)

Also, the y coordinate at \(x=\frac{5}{2}\) is

\(y_v=\left(\frac{5}{2}\right)^2-5\cdot \frac{5}{2}+4\)

Simplify, we get,

\(y_v=-\frac{9}{4}\)

Thus, The vertex of parabola is \(\left(\frac{5}{2},\:-\frac{9}{4}\right)\)

y - intercept is the point where x = 0

Plug x = 0 in given equation \(f(x)=x^2-5x+4\)

\(f(0)=0^2-5(0)+4=4\)

Thus, y - intercept is (0,4)

Now, we calculate x- intercept

x- intercept is where y is equal to 0.

Put f(x) = 0

We have,

\(x^2-5x+4=0\)

Solving the given quadratic equation using quadratic formula ,we have

\(x_{1,\:2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}\)

we have a = 1 , b = -5 and c = 4

\(x_{1,\:2}=\frac{-\left(-5\right)\pm \sqrt{\left(-5\right)^2-4\cdot \:1\cdot \:4}}{2\cdot \:1}\)

Simplify, we have,

\(x_{1,2}=\frac{5\pm\sqrt{9}}{2}\)

Thus, \(x_1=4, x_2=1\)

Thus, The x - intercept are (4,0) and (0,1)

Plot the graph and we obtain as shown below.

View image athleticregina