The piecewise defined function is formed by the following three functions: y = 40, for 0 ≤ x < 15, y = 0.0425 · x² - 3.8 · x + 87.438, for 15 ≤ x < 65 and y = 0.4 · x - 6, for x ≥ 65.
What is the piecewise defined function behind the graph?
In this problem we have a piecewise defined function formed by three functions: (i) Linear equation, (ii) Quadratic equation, (iii) Linear equation. The first function is y = 40, for 0 ≤ x < 15.
The second function can be found based on the knowledge of three points:
y = a · x² + b · x + c
(x₁, y₁) = (15, 40)
40 = 225 · a + 15 · b + c
(x₂, y₂) = (45, 2.5)
2.5 = 2025 · a + 45 · b + c
(x₃, y₃) = (65, 20)
20 = 4225 · a + 65 · b + c
And the quadratic equation is y = 0.0425 · x² - 3.8 · x + 87.438, for 15 ≤ x < 65.
And the latter linear equation is:
y = m · x + b
m = (30 - 20)/(90 - 65)
m = 0.4
And the x-intercept is:
b = y - m · x
b = 20 - 0.4 · 65
b = - 6
The linear equation is y = 0.4 · x - 6, for x ≥ 65.
The piecewise defined function is formed by the following three functions: y = 40, for 0 ≤ x < 15, y = 0.0425 · x² - 3.8 · x + 87.438, for 15 ≤ x < 65 and y = 0.4 · x - 6, for x ≥ 65.
To learn more on piecewise defined functions: https://brainly.com/question/12561612
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