Final answer:
The value of the composition function (f∘h)(−2) is -11.
Step-by-step explanation:
To calculate the value of the composition function (f∘h)(−2), we need to substitute the value of -2 into the function h(x) = x² - 1 first. 
h(-2) = (-2)² - 1 = 4 - 1 = 3. 
Next, we substitute the result, which is 3, into the function f(x) = (x/3) - 12. 
f(3) = (3/3) - 12 = 1 - 12 = -11. 
Therefore, (f∘h)(−2) = -11.