composition of functions Find f(f(4)) if f(x)=14x+13.
It is given that f(x)=14x+13.
(The entire section contains 23 words.)
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To find out f(f(4)), first we'll have to determine the expression of f(f(x)).
This problem requests to apply the rule of composition of 2 functions.
(fof)(x) = f(f(x))
We'll substitute x by f(x):
f(f(x)) = 14*f(x)+13
We'll substitute f(x) by it's expression:
f(f(x)) = 14(14x + 13) + 13
We'll remove the brackets using the distributive law:
f(f(x)) = 196x + 182 + 13
f(f(x)) = 196x + 195
We'll determine f(f(4)):
f(f(4)) = 196*4 + 195
f(f(4)) = 979