solve for x ex 16ex2 4Solutionex 16ex2 4 ex 16ex 42 ex
     solve for x:  e^x + 16e^-x/2 = 4 
  
  Solution
(e^x + 16*e^-x)/2 = 4
(e^x + 16*e^-x) = 4*2
(e^x + 16/e^x) = 8
(e^2x + 16)/e^x = 8
e^2x + 16 = 8*e^x
Put e^x = t
t^2 + 16 = 8*t
t^2 - 8*t + 16 = 0
(t - 4)^2 = 0
Which gives us
t = 4
this means
e^x = 4
ln (e^x) = ln 4
x = ln 4 = 2*0.693
x = 1.386

