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Place value into a function
CONCEPTS
Tips
• The sign, number, and units are all affected when placing a value into an expression
• When placing a value into an expression, always use parentheses when the value is a negative number. This is especially important when that value is being subtracted (5 – (–9))…–9 is the value being inserted into the expression.
PRACTICE PROBLEMS
Question 1 What is f(4) given the functions,
f(x) = 2x + 1 when x < 4
f(x) = - 1/2 * x - 3 when x >= 4?
-- Answer -- -5
The 2nd function is used since x = 4
-1/2* (4) - 3 = -2 - 3 = -5
ACT PRACTICE PROBLEMS
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