185k views
0 votes
Find the equation of the quadratic function g whose graph points are below.

(-3,5)
(-2,3)
g(x) =?
Help!!

User Isioma
by
7.8k points

1 Answer

6 votes

Answer:

To find the equation of the quadratic function g, we can use the general form of a quadratic function:

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

We have two points on the graph of g: (-3, 5) and (-2, 3). We can use these points to form a system of equations and solve for the coefficients a, b, and c.

Using the first point (-3, 5):

5 = a(-3)^2 + b(-3) + c

5 = 9a - 3b + c

Using the second point (-2, 3):

3 = a(-2)^2 + b(-2) + c

3 = 4a - 2b + c

Now we have a system of equations:

9a - 3b + c = 5

4a - 2b + c = 3

We can solve this system of equations to find the values of a, b, and c.

Multiplying the second equation by 3, we get:

12a - 6b + 3c = 9

Subtracting the first equation from this new equation, we eliminate c:

12a - 6b + 3c - (9a - 3b + c) = 9 - 5

12a - 9a - 6b + 3b + 3c - c = 4

3a - 3b + 2c = 4

Now we have a new equation:

3a - 3b + 2c = 4

We can rewrite this equation as:

3a - 3b = 4 - 2c

Dividing both sides by 3, we get:

a - b = (4 - 2c)/3

Now we have an expression for a - b in terms of c.

To find the equation of g(x), we need to express a, b, and c in terms of a single variable. We can choose c as the variable.

Let's set c = k, where k is a constant.

Then, a - b = (4 - 2k)/3

We can rewrite this equation as:

a = (4 - 2k)/3 + b

Now we have a in terms of b and k.

Substituting this expression for a into one of the original equations, we can solve for b.

Using the first equation 5 = 9a - 3b + c:

5 = 9((4 - 2k)/3 + b) - 3b + k

5 = (12 - 6k + 9b)/3 - 3b + k

15 = 12 - 6k + 9b - 9b + 3k

15 = 12 - 3k

Simplifying, we find:

3k = 3

k = 1

Now we have the value of k.

Substituting k = 1 into the expression for a, we get:

a = (4 - 2(1))/3 + b

a = 2/3 + b

Now we have a in terms of b.

Finally, we can write the equation of g(x) using the values of a, b, and c:

g(x) = (2/3 + b)x^2 + bx + 1

So, the equation of the quadratic function g is:

g(x) = (2/3 + b)x^2 + bx + 1

Note that the value of b is still unknown, as it was not determined from the given information.

User Stillenat
by
7.4k points