in a notebook, sketch the graph of the reciprocal function f(x)=1/x, and answer the following questions based on the graph: 1. What is the domain of the function f(x)=1/x? Provide the answer in interval notation, set builder notation, and as inequalities. 2. What is the vertical asymptote of the function f(x)=1/x? 3. Complete the following coordinates of several points located on the graph of the reciprocal function f(x)=1/x. a. What is the y-coordinate when x=−3? b. What is the y-coordinate when x=−1? c. What is the x-coordinate when y=−2? d. What is the x-coordinate when y=−4? e. What is the y-coordinate when x=1/4? f. What is the y-coordinate when x=1/2? g. What is the x-coordinate when y=1? h. What is the x-coordinate when y=1/3? 4. Describe the graph of the function f(x)=1x.

1 answer

1. Domain of the function f(x) = 1/x:

  • Interval Notation: (-∞, 0) ∪ (0, ∞)
  • Set Builder Notation: {x ∈ ℝ | x ≠ 0}
  • Inequalities: x < 0 or x > 0

The domain of the function excludes the value x = 0, where the function is undefined.


2. Vertical asymptote of the function f(x) = 1/x:

The vertical asymptote is at x = 0. As x approaches 0 from the left (negative side), f(x) approaches negative infinity, and as x approaches 0 from the right (positive side), f(x) approaches positive infinity.


3. Coordinates of several points on the graph of f(x) = 1/x:

a. When \( x = -3 \):
\[ f(-3) = 1/(-3) = -1/3 \]
Coordinate: (-3, -1/3)

b. When \( x = -1 \):
\[ f(-1) = 1/(-1) = -1 \]
Coordinate: (-1, -1)

c. When \( y = -2 \):
To find x, set \( f(x) = -2 \):
\[ 1/x = -2 \implies x = -1/2 \]
Coordinate: (-1/2, -2)

d. When \( y = -4 \):
To find x, set \( f(x) = -4 \):
\[ 1/x = -4 \implies x = -1/4 \]
Coordinate: (-1/4, -4)

e. When \( x = 1/4 \):
\[ f(1/4) = 1/(1/4) = 4 \]
Coordinate: (1/4, 4)

f. When \( x = 1/2 \):
\[ f(1/2) = 1/(1/2) = 2 \]
Coordinate: (1/2, 2)

g. When \( y = 1 \):
To find x, set \( f(x) = 1 \):
\[ 1/x = 1 \implies x = 1 \]
Coordinate: (1, 1)

h. When \( y = 1/3 \):
To find x, set \( f(x) = 1/3 \):
\[ 1/x = 1/3 \implies x = 3 \]
Coordinate: (3, 1/3)


4. Description of the graph of the function f(x) = 1/x:

The graph of the function \( f(x) = 1/x \) consists of two branches:

  • The left branch (in the second quadrant) approaches the vertical asymptote (x = 0) as x approaches 0 from the left, and it approaches the horizontal asymptote (y = 0) as x approaches negative infinity. It is a downward sloping curve that never touches the axes.

  • The right branch (in the first quadrant) approaches the vertical asymptote (x = 0) as x approaches 0 from the right, and it approaches the horizontal asymptote (y = 0) as x approaches positive infinity. It is an upward sloping curve that also never touches the axes.

Both branches are symmetric with respect to the origin, exhibiting odd function properties, which is a characteristic of reciprocal functions.

In summary, the graph reflects the behavior of approaching zero but never reaching it, confirming that \( f(x) = 1/x \) has the characteristics of a hyperbola centered at the origin.