Final answer:
To graph the function, start by determining its domain, which is all real numbers, then simplify the expression. Identify the x and y intercepts, symmetry, and asymptotes. Next, use calculus to find intervals of increase, decrease, and concavity and sketch the graph with these details.
Step-by-step explanation:
Graphing a Function Step-by-Step
To graph the function y = 3x - x² / 15 - 8x + x², certain steps must be followed:
- Find the domain of the function: Since there are no denominators or even roots, the domain is all real numbers.
- Simplify the function if possible: The simplified form is y = -x² / 15 + 5x.
- Find the x and y intercepts: Set y to 0 to find x-intercepts and x to 0 to find the y-intercept.
- Determine any odd or even symmetry: This is a quadratic function, so it has even symmetry (symmetrical about the y-axis).
- Identify all vertical and horizontal asymptotes: There are none for this function as it is a polynomial.
- Find intervals of increase & decrease, and any local max or min points using a sign chart: Calculate the derivative and analyze the signs to find these intervals.
- Determine intervals of concavity and any inflection points with a sign chart: Calculate the second derivative and use it to determine concavity.
- Sketch the function showing all details: Plot intercepts, max and min points, and concavity to sketch the graph.