451,450 views
24 votes
24 votes
Can you help with quadratic graph below check if I am going correct

Can you help with quadratic graph below check if I am going correct-example-1
User Lynnette
by
2.6k points

1 Answer

13 votes
13 votes

A quadratic function in standard fomr is:


y=ax^2+bx+c

a is the number multiplying the quadratic term. b is the number multiplying the x and c is the term without x.

In this case we have:


f(x)=-x+6-x^2

Now if we rearrange as above:


f(x)=-x^2-x+6

And now we can clearly see that:

a = -1

b = -1

c = 6

now for the table we need to input each term in it. The third row in the x section of the table will be always 6, because is a constant which does not depend of x.

We need to use additional values to the given ones to complete the interval [-4, 3].

We'll use:

-4, -3, -2, -1, -0.5, 0, 1, 2

Now, for -x², the row is:


\begin{gathered} -(-4)^2=-16 \\ -(-3)^2=-9 \\ -(-2)^2=-4 \\ -(-1)^2=-1 \\ -(-0.5)^2=-0.25 \\ -(0)^2=0 \\ -(1)^2=-1 \\ -(2)^2=-4 \\ -(3)^2=-9 \end{gathered}

The -x row is:


\begin{gathered} -(-4)=4 \\ -(-3)=3 \\ -(-2)=2 \\ -(-1)=1 \\ -(-0.5)=0.5 \\ -(0)=0 \\ -(1)=-1 \\ -(2)=-2 \\ -(3)=-3 \end{gathered}

Finally we need to complete the y row. This is the sum of the three values in the x:

The y row is:


\begin{gathered} -16+4+6=-6 \\ -9+3+6=0 \\ -4+2+6=4 \\ -1+1+6=6 \\ -0.25+0.5+6=6.25 \\ 0+0+6=6 \\ -1-1+6=4 \\ -4-2+6=0 \\ -9-3+6=6 \end{gathered}

With that, the table is complete, and the problem is solved.

User Marco Staffoli
by
2.8k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.