SAT Subject Test Mathematics Level 2

(Marvins-Underground-K-12) #1

COMPOUND FUNCTIONS


When one function is written inside another function’s parentheses, apply the inside function first:


Then apply the outside function to the result:


The answer is (C).


Notice that there’s a difference between h(g(6)) and g(h(6)). In the latter, you’re to apply the
function h first and then the function g to the result. The order makes a difference: h(g(6)) ≈ 5.61,
but g(h(6)) ≈ 5.55 (which is, of course, included as a distracter).


WATCH THOSE PARENTHESES


(E) 6.16


f(g(x)) means   apply   g   first   and then    apply   f   to  the result.
g(f(x)) means apply f first and then apply g to the result.
f(x)g(x) means apply f and g separately and then multiply the results.
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