Using the graph of f(x) = log10x below, approximate the value of y in the equation 10^y = 3.

Assuming log10x means log(base 10)x 

Let's rewrite 10^y = 3 by taking the log(base 10) of both sides
log (10^y) = log (3)                 Remember that log(10^y) = y
y = log (3) 
This is the same as our function f(x) = log(x), or f(3) = log(3)
Consult our graph of f(x) to find the y value at x=3
Checking the graph, we can find the value of y at point x=3
The value is .477. Therefore, y =.477, or about 1/2