To find the vertex of the quadratic function given by the equation:
\[ y = -0.003x^2 + 0.053x + 1.992 \]
we can use the formula for the x-coordinate of the vertex of a parabola represented by the equation \( y = ax^2 + bx + c \):
\[ x = -\frac{b}{2a} \]
Here, \( a = -0.003 \) and \( b = 0.053 \).
Step 1: Calculate the x-coordinate of the vertex
\[ x = -\frac{0.053}{2 \cdot -0.003} = -\frac{0.053}{-0.006} \approx 8.8333 \]
Step 2: Calculate the y-coordinate of the vertex
Now substitute this x value back into the original equation to find the y-coordinate:
\[ y = -0.003(8.8333)^2 + 0.053(8.8333) + 1.992 \]
Calculating \( (8.8333)^2 \):
\[ 8.8333^2 \approx 78.0735 \]
Now substituting into \( y \):
\[ y \approx -0.003 \cdot 78.0735 + 0.053 \cdot 8.8333 + 1.992 \]
\[ y \approx -0.2342 + 0.4687 + 1.992 \]
\[ y \approx 1.2265 \]
Vertex Interpretation
Thus, the vertex is approximately:
\[ \text{Vertex} = (8.833, 1.227) \]
Answer for Part a:
The vertex of the graph of this model is \( v = (8.833, 1.227) \).
Interpretation: The vertex indicates that at approximately 8.833 years after 2015 (which is around the year 2024), the crude oil production is projected to reach around 1.227 billion barrels.
Part b: Predicting crude oil production in 2038
To find the production in 2038, we calculate \( x \) for that year. Since \( x \) represents the years after 2015:
\[ x = 2038 - 2015 = 23 \]
Now substitute \( x = 23 \) back into the original equation:
\[ y = -0.003(23)^2 + 0.053(23) + 1.992 \]
Calculating \( (23)^2 \):
\[ 23^2 = 529 \]
Now substituting into \( y \):
\[ y = -0.003 \cdot 529 + 0.053 \cdot 23 + 1.992 \]
\[ y \approx -1.587 + 1.219 + 1.992 \]
\[ y \approx 1.624 \]
Prediction for Part b:
The model predicts that the crude oil production in 2038 will be approximately 1.624 billion barrels.
Part c: Graphing the Function
To graph the function \( y = -0.003x^2 + 0.053x + 1.992 \) for the years from 2015 to 2035, we consider \( x \) values from 0 (2015) to 20 (2035). Use points such as:
- Calculate \( y \) for integers \( x = 0, 1, 2, \ldots, 20 \).
- You can create a table of \( x \) values (years after 2015) and their corresponding \( y \) (billions of barrels).
- Finally, plot these points on a graph with \( x \) on the horizontal axis and \( y \) on the vertical axis.
Note: You could use software, a graphing calculator, or a spreadsheet application to plot this for better accuracy and visualize the function.
If you need assistance with graphing using specific tools or software, feel free to ask!