SOLUTION: How do you find the x and y intercepts of a log function? Example: f(x) = {{{ log( 2, (x+4) ) }}} I know that you need to let one variable equal 0 to solve for the other, b

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: How do you find the x and y intercepts of a log function? Example: f(x) = {{{ log( 2, (x+4) ) }}} I know that you need to let one variable equal 0 to solve for the other, b      Log On


   

Question 316242: How do you find the x and y intercepts of a log function?
Example: f(x) = +log%28+2%2C+%28x%2B4%29+%29+
I know that you need to let one variable equal 0 to solve for the other, but I am completely lost when it comes to the log on what to do! I've heard to cancel it out on one side (when solving for x) you need to change the x of the log (the 4 in this case) to an exponent on the base, but I'm not sure...
Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29+=+log%282%2C%28x%2B4%29%29
+y+=+log%282%2C%28x%2B4%29%29
2%5Ey+=+x%2B4
Let x = 0
2%5Ey+=+4
2%5Ey+=+2%5E2
y+=+2
one intercept is (0,2)
2%5Ey+=+x%2B4
2%5E0+=+x%2B4
1+=+x%2B4
x+=+-3
another intercept is (-3,0)
See this for a plot
http://www.wolframalpha.com/input/?i=log2%28x%2B4%29