Functions or Functional Notations are referred by the letter ‘f’ and written as f(x), sometimes in the form of g(x), h(a) etc.
Solved Examples
Question 1: Represent y =
\(\begin{array}{l}x^{2}\end{array} \)
+ 4x + 1 using function notation and find the value of y at x = 3.
Solution:
Given function is,
y =
By using function notation,
f(x) =
Value of y at x = 3Â means f(3).
So, f(3) =
y =
\(\begin{array}{l}x^{2}\end{array} \)
+ 4x + 1By using function notation,
f(x) =
\(\begin{array}{l}x^{2}\end{array} \)
+ 4x + 1Value of y at x = 3Â means f(3).
So, f(3) =
\(\begin{array}{l}3^{2}\end{array} \)
+ 4\(\begin{array}{l}\times\end{array} \)
3 + 1 = 9 + 12 + 1 = 22Question 2: Represent the given function y =
\(\begin{array}{l}x^{3}\end{array} \)
– 4x using function notation and find the value of y at x = 2.
Solution:
Given function is,
y =
By using function notation,
f(x) =
The value of y at x = 2Â means f(2).
Therefore, f(2) =
y =
\(\begin{array}{l}x^{3}\end{array} \)
– 4xBy using function notation,
f(x) =
\(\begin{array}{l}x^{3}\end{array} \)
– 4xThe value of y at x = 2Â means f(2).
Therefore, f(2) =
\(\begin{array}{l}2^{3}\end{array} \)
– 4 \(\begin{array}{l}\times\end{array} \)
2 = 8 -8 = 0
