At what stage will 81 new friends know about your summer job?
1 answer:
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Answer:
Step-by-step explanation:
There are 3 ways to find the other x intercept.
1) Polynomial Long Division.
Divide x^2 - 3x + 2 by the binomial x - 2, because by the Factor Theorem if a is a root of a polynomial then x - a is a factor of said polynomial.
2) Just solving for x when y = 0, by using the quadratic formula.
.
So the other x - intercept is at (1, 0)
3) Using Vietta's Theorem regarding the solutions of a quadratic
Namely, the sum of the solutions of a quadratic equation is equal to the quotient between the negative coefficient of the linear term divided by the coefficient of the quadratic term.
And the product between the solutions of a quadratic equation is just the quotient between the constant term and the coefficient of the quadratic term.
These relations between the solutions give us a brief idea of what the solutions should be like.
First, we are going to find the vertex of our quadratic. Remember that to find the vertex 
of a quadratic equation of the form 
, we use the vertex formula 
, and then, we evaluate our equation at 
to find 
.
We now from our quadratic that
and 
, so lets use our formula:
Now we can evaluate our quadratic at 8 to find:
So the vertex of our function is (8,-72)
Next, we are going to use the vertex to rewrite our quadratic equation:
The x-coordinate of the minimum will be the x-coordinate of the vertex; in other words: 8.
We can conclude that:
The rewritten equation is
The x-coordinate of the minimum is 8
We now from our quadratic that
Now we can evaluate our quadratic at 8 to find
So the vertex of our function is (8,-72)
Next, we are going to use the vertex to rewrite our quadratic equation:
The x-coordinate of the minimum will be the x-coordinate of the vertex; in other words: 8.
We can conclude that:
The rewritten equation is
The x-coordinate of the minimum is 8