Composition of Functions · Exercise 96

The function $A\left(d\right)$ gives the pain level on a scale of 0 to 10 experienced by a patient with $d$ milligrams of a pain-reducing drug in her system. The milligrams of the drug in the patient’s system after $t$ minutes is modeled by $m\left(t\right).$ Which of the following would you do in order to determine when the patient will be at a pain level of 4?

ⓐEvaluate $A\left(m\left(4\right)\right).$
ⓑEvaluate $m\left(A\left(4\right)\right).$
ⓒSolve $A\left(m\left(t\right)\right)=4.$
ⓓSolve $m\left(A\left(d\right)\right)=4.$

OpenStax, Algebra and Trigonometry 2e · §3.4 Composition of Functions · Exercise 96