192k views
2 votes
Please helpFind the vertex, roots/zeros and y-intercept of the following.

Please helpFind the vertex, roots/zeros and y-intercept of the following.-example-1

1 Answer

2 votes

In a quadratic equation like:


f(x)=ax^2+bx+c

To find the vertex use the next formula:

x-coordinate of the vertex:


h=-(b)/(2a)

y-coordinate of the vertex evaluate the equation for x=h


f(h)=ah^2+bh+c

To find the zeros or x-intercepts. Equal the function to zero and solve x.

To find the Y-intercept evaluate the equation for x=0

-----------------------------------------------

For the given equations:


f(x)=x^2

Vertex:


\begin{gathered} a=1,b=0 \\ \\ h=-(0)/(2(1))=0 \\ \\ f(0)=0^2=0 \\ \\ \text{Coordiantes of the vertex:} \\ (0,0) \end{gathered}

y intercept is 0 (coordinates (0,0))

Zeros: in (0,0)


\begin{gathered} f(x)=0 \\ x^2=0 \\ x=\sqrt[]{0} \\ x=0 \end{gathered}

-------------------------------------


f(x)=x^2+5

Vertex:


\begin{gathered} a=1,b=0 \\ \\ h=-(0)/(2(1))=0 \\ \\ f(0)=0^2+5=5 \\ \\ \text{Coordinates of the vertex:} \\ (0,5) \end{gathered}

y-intercpet is 5 (coordinates (0,5)

Zeros:


\begin{gathered} f(x)=0 \\ x^2+5=0 \\ x^2=-5 \\ x=\sqrt[]{-5} \\ \end{gathered}

As the square root of a negative number is not a real number the function has not zeros (doesn't cross the x-axis)

User Csl
by
3.9k points