A) 9
B) 15
C) (approximately 9.43)
D) (approximately 10.82)
Here’s How to Crack It
Start by finding the x- and y-intercepts of the line. When an equation is in y = mx + b form, the y-intercept
is b. So, the y-intercept is at the point (0, –6). To find the x-intercept, you need a point where the y value
is 0, just like how the y-intercept has an x value of 0. So, plug in 0 for y in the equation: 0 = x − 6, so x
= 6, and x = 6 = 9. The x-intercept, then, is (9, 0).
Now draw a right triangle and use the Pythagorean Theorem to calculate the distance: 6^2 + 9^2 = c^2 , so c^2 =
117, and the distance is , which is (D).
Graphing Functions
One type of function question you might be asked is how the graph of a function would shift if you added a
value to it.
Here is a quick guide (c is a constant) for the graph of f(x) = x^2 :
For f(x) + c, the graph will shift up c units, as shown in the diagram below: