GED Mathematical Reasoning TestAlgebraic Problem Solving with Graphs and FunctionsEasy
A technician is calibrating a sensor. The sensor's output, in volts, is represented by the function f(x) = 2x - 3, where x is the input signal. What is the value of the output when the input signal is 5?
- A2 volts
- B13 volts
- C10 volts
- D7 volts
Show answer & explanationAnswer & explanation
Correct answer: D. 7 volts
To find the output value, substitute the input signal x=5 into the given function f(x) = 2x - 3. This yields f(5) = 2(5) - 3 = 10 - 3 = 7.
Why the other options are wrong
- A. This would be the result if 5 was subtracted from 3, or if the input was 2.5.
- B. This would be the result if the subtraction was incorrectly performed as addition.
- C. This would be the result if only the multiplication 2 * 5 was performed.
Evaluating a Function
Evaluating a function means substituting a given input value into the function's expression to find the corresponding output value.
- Replace the variable (usually x) with the given input number.
- Follow the order of operations (PEMDAS/BODMAS).
- The result is the function's output for that specific input.
Memory trick: Input goes in, output comes out, like a math machine!