Praxis Core Academic Skills for Educators: Mathematics (5733)Algebra and FunctionsEasy

A scientist is observing the growth of a plant. The height of the plant, H(d), in centimeters, after 'd' days is modeled by the function H(d) = 0.5d + 12. What is the predicted height of the plant after 10 days?

  1. A62 cm
  2. B12.5 cm
  3. C22 cm
  4. D17 cm
Show answer & explanation

Correct answer: D. 17 cm

To find the predicted height after 10 days, substitute d=10 into the given function H(d) = 0.5d + 12. This yields H(10) = 0.5(10) + 12 = 5 + 12 = 17 cm.

Why the other options are wrong

  • A. This would be the result if the growth rate was 5d instead of 0.5d.
  • B. This would be the height if the growth rate was 0.05d instead of 0.5d.
  • C. This might result from incorrectly multiplying 0.5 by 10 then adding 12 (e.g., 10 + 12 = 22, ignoring the 0.5).

Function Evaluation

Function evaluation is the process of determining the value of a function for a given input value. It involves substituting the input into the function's expression.

  • Replace the variable with the given input value.
  • Follow the order of operations (PEMDAS/BODMAS) to simplify.
  • The result is the output value of the function for that input.

Memory trick: Input goes IN, Output comes OUT!

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