ACT Math — Functions — Drill 2

About This Drill

ACT Math — Functions — Drill 2 is a Math practice drill covering Functions. It contains 5 original questions created by Brian Stewart, a Barron's test prep author with over 20 years of tutoring experience.

This ACT Functions drill covers evaluating piecewise functions, modeling exponential growth in context, solving for an input given a specified output, evaluating logarithmic expressions, and performing algebraic composition of two functions.

Questions in This Drill

1. A function f(x) is defined as follows:
   f(x) = 3x + 1, if x < 2
   f(x) = x² − 3, if x ≥ 2
   
   What is f(−1) + f(4)?
2. The number of users on a new app is modeled by N(t) = 1,200 · (1.5)^t, where t is the number of months since launch. What does the value 1,200 represent in this model?
3. If h(x) = 4x − 9 and h(a) = 19, what is the value of a?
4. If f(x) = log₂(x + 4), what is f(28)?
5. Let f(x) = 2x + 1 and g(x) = x² − 4. Which of the following is equivalent to f(g(x))?