Mathorio
Answer key
Graphing the Tangent Function
Show your work for each problem.
- 1.What is the period of ?
- a)
- b)
- c)
- d)
Answer:
The period of is , not like sine and cosine. This is because for all in the domain.
- 2.Where does the first positive asymptote of occur?
- a)
- b)
- c)
- d)
Answer:
The asymptotes of occur where . The first positive value where this happens is .
- 3.What is ?
Answer: 0
. The tangent function passes through the origin.
- 4.What is the range of ?
- a)
- b)
- c)
- d)
Answer:
The range of is all real numbers . Unlike sine and cosine which are bounded between and , tangent can take any real value.
- 5.What is ?
Answer: 1
. This is a key reference point on the tangent graph.
- 6.What is the period of ? Give your answer as a fraction of (e.g., enter 'pi/2' for ).
Answer: pi/2
For , the period is . With , the period is .
- 7.Which transformation does the '3' represent in ?
- a)Vertical stretch by factor of 3
- b)Vertical shift up by 3
- c)Horizontal compression by factor of 3
- d)Period change to
Answer: Vertical stretch by factor of 3
The coefficient 3 in front of stretches the graph vertically by a factor of 3. Every y-value is multiplied by 3, making the curve steeper.
- 8.Find the period and the first positive asymptote of .
Answer: pi/6
- What is the formula for the period of ? pi/|b|
- What is in ? 3
- Calculate the period: . Write as fraction of pi. pi/3
- The first positive asymptote is at half the period. What is ? pi/6
- 9.What happens to the asymptotes when we graph ?
- a)They shift right by
- b)They don't change position
- c)They shift down by
- d)They shift left by
Answer: They shift right by
The transformation shifts the entire graph, including asymptotes, to the right by . The new asymptotes are at , etc.
- 10.Find where equals 1 for in .
Answer: pi/4, 5pi/4
- At what angle in the first quadrant does ? pi/4
- The period of tangent is . What is ? 5pi/4
- Is less than ? yes
- List both solutions in : pi/4, 5pi/4
- 11.What is the period of ? Give your answer as a multiple of (e.g., '2pi' for ).
Answer: 2pi
Period = . The graph is stretched horizontally, taking twice as long to complete one cycle.
- 12.Graph . Describe how it differs from .
Answer: reflected over x-axis
- What does the negative sign in front of a function do? reflection
- At , what is ? -1
- Do the asymptotes change position? no
- Describe the transformation in one phrase: reflected over x-axis
- 13.For , what is the equation of the midline?
- a)
- b)There is no midline
- c)
- d)
Answer:
The vertical shift of moves the entire graph up by 2 units. The midline (where the function crosses between periods) is at .
- 14.Find the asymptotes of in the interval .
Answer: pi/4, 3pi/4
- Rewrite as . What is the phase shift? pi/2
- For , asymptotes are at . With a shift of , where is the first asymptote? pi/4
- The period is . What is the next asymptote after ? 3pi/4
- List the asymptotes in : pi/4, 3pi/4
- 15.Which statement is TRUE about the graph of ?
- a)It has a maximum value of 1
- b)It is an odd function:
- c)It is continuous for all real numbers
- d)It is an even function:
Answer: It is an odd function:
The tangent function is odd because . The graph has point symmetry about the origin.