Question 1179038:  Graph f as a solid line and F-1 as a dashed line in the same rectangular coordinate space. Use interval notation to give the domain and range of f and F-1.
 
f(x) = 3x - 2 
 
 Answer by CPhill(1987)      (Show Source): 
You can  put this solution on YOUR website! Here's how to graph f and f⁻¹ and find their domain and range:
 
**1. Graph f(x) = 3x - 2:**
 
* This is a linear function with a slope of 3 and a y-intercept of -2. 
* Plot the y-intercept (0, -2). 
* Use the slope to find another point: from (0, -2), move up 3 units and right 1 unit to get (1, 1). 
* Draw a solid line through these points.
 
**2. Find f⁻¹(x):**
 
* Replace f(x) with y: y = 3x - 2 
* Swap x and y: x = 3y - 2 
* Solve for y: 
    * x + 2 = 3y 
    * y = (x + 2) / 3 
* Replace y with f⁻¹(x): f⁻¹(x) = (x + 2) / 3
 
**3. Graph f⁻¹(x) = (x + 2) / 3:**
 
* This is also a linear function with a slope of 1/3 and a y-intercept of 2/3. 
* Plot the y-intercept (0, 2/3). 
* Use the slope to find another point: from (0, 2/3), move up 1 unit and right 3 units to get (3, 5/3). 
* Draw a dashed line through these points.
 
**4. Domain and Range:**
 
* **f(x) = 3x - 2:** 
    * Domain: All real numbers (-∞, ∞) 
    * Range: All real numbers (-∞, ∞) 
* **f⁻¹(x) = (x + 2) / 3:** 
    * Domain: All real numbers (-∞, ∞) 
    * Range: All real numbers (-∞, ∞)
 
**Note:**
 
* The graphs of f and f⁻¹ are reflections of each other across the line y = x. 
* Since both functions are linear, their domains and ranges are all real numbers. 
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