Verify that f has an inverse. then use the function f and the given real number a to find (f −1)'(a). (hint: see example 1. if an answer does not exist, enter dne.) function real number f(x) = x + 2 x − 6 , x > 6 a = 3
f(x) = x + 2 x − 6------------ > f(x) = 3x− 6 The function is continuous in the interval (-∞,∞) y=3x-6--------- >3x=y+6------> x=(y+6)/3
Interchange x and y to find the inverse function (f −1)(x)=(x+6)/3----> (x/3)+2 Apply derivative with respect to x (f −1)'(x)=1/3 for all values of x (f −1)'(x)=1/3