Question 433021
  <pre><font face = "Tohoma" size = 4 color = "indigo"><b>
Hi
*[tex \LARGE \ \ \ \ \  \ \ \ b^y = x \ \ \ \ \ \Rightarrow\ \ \ \ \ \ \ y = \log_b(x) ]
 e^(-x)= 1/2 = ln(.5) = -x
               -.69 = -x
                 .69 = x