If you have a graphing calculator, I would suggest always drawing the
graph first. Here is the graph:
The graph has a vertical asymptote x = -17 (the green line).
Logarithms are only taken of positive numbers. To get that domain,
set x + 17 > 0
x > -17
The domain is {x|x > -17}
In interval notation that's written (-17,)
To find the y-intercept:
Set x = 0,
y =
y= = = 10.31560769
So the y-intercept is (0, 10.31560769)
To find the x-intercept,
Set y = 0
y = = 0
= 0
Divide both sides by 4
= 0
Write the equivalent exponential form of that equation:
x + 17 = 30
x + 17 = 1
x = -16
So the x-intercept is (-16,0). As you see all these check with the graph.
Edwin