The <em>piecewise defined</em> 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.
<h3>What is the piecewise defined function behind the graph?</h3>
In this problem we have a <em>piecewise defined</em> function formed by three functions: (i) <em>Linear</em> equation, (ii) <em>Quadratic</em> equation, (iii) <em>Linear</em> equation. The <em>first</em> function is y = 40, for 0 ≤ x < 15.
The <em>second</em> 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 <em>quadratic</em> equation is y = 0.0425 · x² - 3.8 · x + 87.438, for 15 ≤ x < 65.
And the <em>latter linear</em> 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 <em>linear</em> equation is y = 0.4 · x - 6, for x ≥ 65.
The <em>piecewise defined</em> 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: brainly.com/question/12561612
#SPJ1