consider the equation below

f(x)=e^(7x)+e^(-x)

find the intervals on which f is increasing and decreasing (enter your answers using interval notation)

find the local minimum of f.

find the interval on which f is concave up.

1 answer

http://www.mathsisfun.com/data/function-grapher.php

f' = 7 e^7x - e^-x
when is that zero?

7 e^7x = e^-x
7 e^8x = 1
e^8x = 1/7
8 x = ln(1/7)
x = -.243 at min