Answer:
f(1/4) = 1/12
Explanation:
f(x) = 4x^2 - 2/3 x is a function. The name of the function is simply the letter f. It tells you a rule. f(x) is the same as y.
It is the same as having
y = 4x^2 - 2/3 x
For each value of x you are given, you can calculate a corresponding value of y. Instead of calling y, y, we call y "f(x)" which is a way of showing that this relation is a function.
If you were given
y = 4x^2 - 2/3 x and were asked to find the value of y when x = 1/4, what would you do?
You would substitute 1/4 for x in the expression 4x^2 - 2/3 x, and you'd find the value of y.
Being asked to find f(1/4) for function f(x) = 4x^2 - 2/3 x means exactly the same. It means what is the value of the function when x = 1/4? What is the y value corresponding to an x value of 1/4?
Let's calculate it:
f(x) = 4x^2 - 2/3 x
To show we are evaluating the function at an x value of 1/4, we use the notation f(1/4). f(1/4) means find the value of y for function f when x = 1/4. We replace x with 1/4 and do the math.
f(1/4) = 4(1/4)^2 - (2/3)(1/4)
f(1/4) = 4(1/16) - 2/12
f(1/4) = 4/16 - 2/12
f(1/4) = 1/4 - 2/12
f(1/4) = 3/12 - 2/12
f(1/4) = 1/12