All Trigonometry Resources
Example Questions
Example Question #1 : Determine Which Values Of Trigonometric Functions Are Undefined
Which of the following trigonometric functions is undefined?
Trigonometric functions are equal to 0, 1, -1 or undefined when the angle lies on an axis, meaning that the angle is equal to 0, 90, 180 or 270 degrees (0, (pi)/2, pi or 3(pi)/2 in radians.) Trigonometric functions are undefined when they represent fractions with denominators equal to zero. Cosecant is the reciprocal of sine, so the cosecant of any angle x for which sin x = 0 must be undefined, since it would have a denominator equal to 0. The value of sin (0) is 0, so the cosecant of 0 must be undefined.
Example Question #1 : Determine Which Values Of Trigonometric Functions Are Undefined
Which of the following trigonometric functions is undefined?
Trigonometric functions are equal to 0, 1, -1 or undefined when the angle lies on an axis, meaning that the angle is equal to 0, 90, 180 or 270 degrees (0, (pi)/2, pi or 3(pi)/2 in radians.) Trigonometric functions are undefined when they represent fractions with denominators equal to zero. Tangent is defined as the ratio between the side length opposite to the angle in question and the side length adjacent to it (TOA, or tan x = opposite/adjacent). In a triangle created by the angle x and the x-axis, the adjacent side length lies along the x-axis; however, when the angle x lies on the y-axis, no length can be drawn along the x-axis to represent the angle. As a result, the denominator of the fraction created by the definition tan x = opposite/adjacent is equal to zero for any angle along the y-axis (90 or 270 degrees, or pi/2 or 3pi/2 in radians.) Therefore, tan 3(pi)/2 is undefined.
Example Question #1 : Determine Which Values Of Trigonometric Functions Are Undefined
Which of the following trigonometric functions is undefined?
Trigonometric functions are equal to 0, 1, -1 or undefined when the angle lies on an axis, meaning that the angle is equal to 0, 90, 180 or 270 degrees (0, (pi)/2, pi or 3(pi)/2 in radians.) Trigonometric functions are undefined when they represent fractions with denominators equal to zero. Cosecant is the reciprocal of sine, so the cosecant of any angle x for which sin x = 0 must be undefined, since it would have a denominator equal to 0. The value of sin (pi) is 0, so the cosecant of pi must be undefined.
Example Question #121 : Trigonometric Functions And Graphs
Which of the following trigonometric functions is undefined?
Trigonometric functions are equal to 0, 1, -1 or undefined when the angle lies on an axis, meaning that the angle is equal to 0, 90, 180 or 270 degrees (0, (pi)/2, pi or 3(pi)/2 in radians.) Trigonometric functions are undefined when they represent fractions with denominators equal to zero. Tangent is defined as the ratio between the side length opposite to the angle in question and the side length adjacent to it (TOA, or tan x = opposite/adjacent). In a triangle created by the angle x and the x-axis, the adjacent side length lies along the x-axis; however, when the angle x lies on the y-axis, no length can be drawn along the x-axis to represent the angle. As a result, the denominator of the fraction created by the definition tan x = opposite/adjacent is equal to zero for any angle along the y-axis (90 or 270 degrees, or pi/2 or 3pi/2 in radians.) Therefore, tan (pi)/2 is undefined.
Example Question #1 : Determine Vertical Shifts
Let be a function defined as follows:
The 4 in the function above affects what attribute of the graph of ?
Vertical shift
Phase shift
Period
Amplitude
Vertical shift
The period of the function is indicated by the coefficient in front of ; here the period is unchanged.
The amplitude of the function is given by the coefficient in front of the ; here the amplitude is -1.
The phase shift is given by the value being added or subtracted inside the function; here the shift is units to the right.
The only unexamined attribute of the graph is the vertical shift, so 4 is the vertical shift of the graph. A vertical shift of 4 means that the entire graph of the function will be moved up four units (in the positive y-direction).
Example Question #1 : Determine Vertical Shifts
Let be a function defined as follows:
What is the vertical shift in this function?
The period of the function is indicated by the coefficient in front of ; here the period is unchanged.
The amplitude of the function is given by the coefficient in front of the ; here the amplitude is 3.
The phase shift is given by the value being added or subtracted inside the cosine function; here the shift is units to the right.
The only unexamined attribute of the graph is the vertical shift, so -3 is the vertical shift of the graph. A vertical shift of -3 means that the entire graph of the function will be moved down three units (in the negative y-direction).
Example Question #1 : Determine Vertical Shifts
The graph below shows a translated sine function. Which of the following functions could be shown by this graph?
A normal graph has its y-intercept at . This graph has its y-intercept at . Therefore, the graph was shifted down three units. Therefore the function of this graph is .
Example Question #1 : Determine Vertical Shifts
This graph shows a translated cosine function. Which of the following could be the equation of this graph?
The correct answer is . There are no sign changes with vertical shifts; in other words, when the function includes , it directly translates to moving up three units. If you thought the answer was , you may have spotted the y-intercept at and jumped to this answer. However, recall that the y-intercept of a regular function is at the point . Beginning at and ending at corresponds to a vertical shift of 3 units.
Example Question #1 : Determine Vertical Shifts
Consider the function . What is the vertical shift of this function?
The general form for the secant transformation equation is . represents the phase shift of the function. When considering we see that , so our vertical shift is and we would shift this function units up from the original secant function’s graph.
Example Question #1 : Determine Vertical Shifts
Which of the following is the graph of with a vertical shift of ?
The graph of with a vertical shift of is shown below. This can also be expressed as .
Here is a graph that shows both and , so that you can see the "before" and "after." The original function is in blue and the translated function is in purple.
The graphs of the incorrect answer choices are (no vertical shift applied), (shifted upwards instead of downwards), (amplitude modified, and shifted upwards instead of downwards), and (shifted downwards 3 units, but this is not the correct original graph of simply since the amplitude was modified.)
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