ANSWERS
i) a) f(x) + 2
b) f(-x)
c) 2f(x)
ii) Exponential function
EXPLANATION
i) a) This transformation is a vertical translation 2 units up. To graph this function, we just have to copy the graph of f(x) and move it to 2 units up. Note that in the given graph, 1 unit is represented by 2 squares.
See graph in the Answers section.
b) This other transformation is a reflection over the y-axis. To graph this function, we have to draw function f(x) but flipped vertically, as if the y-axis were a mirror.
See graph in the Answers section.
c) This last transformation is a vertical stretch by a factor of 2. To graph this function, we have to take the y-values of f(x) and multiply them by 2, with the same x-value. If we do this for 3 or 4 points, and we follow the shape of the function we can graph it correctly.
See graph in the Answers section.
ii) A function is an expression that defines the relationship between two variables, one is called the independent variable and the other is the dependent variable. We use functions to show how the dependent variable changes when the independent variable changes. For example, if we want to show how fast a person is moving, we would have a function where the independent variable is time and the dependent variable is the person's position.
This function is an exponential function. It has all the characteristics for the domain graphed:
• The range is y > 0
,
• There is a horizontal asymptote at the x-axis when x approaches negative infinity
,
• The graph increases to infinity when x approaches positive infinity
,
• The graph is continuous and smooth
Also, when x = 0, f(0) = 1, so the function most likely represents the equation,
Where a and b are real numbers.