All Flashcards
What are the key differences between the graphs of and ?
: Starts at (0,0). | : Starts at (0,1).
Compare the symmetry of sine and cosine functions.
Sine: Odd function, symmetric about the origin. | Cosine: Even function, symmetric about the y-axis.
Compare the x-intercepts of and in the interval .
: 0, , | : ,
Compare the maximum values of and .
: Maximum value of 1 at | : Maximum value of 1 at 0 and
Compare the minimum values of and .
: Minimum value of -1 at | : Minimum value of -1 at
Compare the effect of a positive phase shift on and .
Both shift the graph to the right by the amount of the phase shift. | The overall shape remains the same, just translated.
Compare the effect of changing the amplitude of and .
Both stretch or compress the graph vertically. | A larger amplitude makes the peaks and troughs more extreme.
Compare the effect of changing the period of and .
Both compress or stretch the graph horizontally. | A smaller period means more cycles within the same interval.
Compare the effect of a vertical shift on and .
Both move the entire graph up or down by the shift amount. | The midline of the graph changes accordingly.
Compare the relationship between sine and cosine to the unit circle.
Sine: y-coordinate on the unit circle. | Cosine: x-coordinate on the unit circle.
What does the amplitude of a sine graph tell you?
It indicates the maximum displacement of the graph from its midline, representing the maximum value the function attains.
What does the period of a cosine graph tell you?
It represents the length of one complete cycle of the cosine function before the pattern repeats.
How can you identify the phase shift from a sine or cosine graph?
By observing the horizontal displacement of the graph compared to the standard sine or cosine function. Where does the cycle BEGIN relative to the origin?
How does the graph of differ from the graph of ?
The graph of is a reflection of the graph of over the x-axis.
How does the graph of differ from the graph of ?
The graph of is a reflection of the graph of over the x-axis.
What does a vertical shift in a sine or cosine graph indicate?
It indicates that the entire graph has been moved up or down, changing the midline of the function.
How can you determine the equation of a sine or cosine function from its graph?
Identify the amplitude, period, phase shift, and vertical shift, and then plug these values into the general form of the sine or cosine function.
What does the steepness of a sine or cosine graph indicate?
The steepness relates to how quickly the function's value is changing at that point. Steeper sections indicate more rapid change.
How are the x-intercepts of a sine or cosine graph related to the unit circle?
The x-intercepts correspond to the angles on the unit circle where the sine (y-coordinate) or cosine (x-coordinate) is equal to zero.
How can you tell if a sine or cosine graph has been stretched or compressed horizontally?
By examining the period of the graph. A shorter period indicates horizontal compression, while a longer period indicates horizontal stretching.
Explain how the unit circle relates to the sine function's graph.
The y-coordinates of points on the unit circle, as you move counterclockwise around the circle, correspond to the values of the sine function at those angles.
Explain how the unit circle relates to the cosine function's graph.
The x-coordinates of points on the unit circle, as you move counterclockwise around the circle, correspond to the values of the cosine function at those angles.
Describe the key features of the sine graph.
Starts at (0,0), oscillates between -1 and 1, has a period of , and is an odd function (symmetric about the origin).
Describe the key features of the cosine graph.
Starts at (0,1), oscillates between -1 and 1, has a period of , and is an even function (symmetric about the y-axis).
Explain the effect of changing the amplitude of a sine or cosine function.
Changing the amplitude stretches or compresses the graph vertically. A larger amplitude means a greater maximum and minimum value.
Explain the effect of changing the period of a sine or cosine function.
Changing the period compresses or stretches the graph horizontally. A smaller period means the function oscillates more frequently.
Explain the effect of a vertical shift on a sine or cosine function.
A vertical shift moves the entire graph up or down. Adding a constant 'D' to the function shifts it up by 'D' units.
Explain the effect of a phase shift on a sine or cosine function.
A phase shift moves the entire graph left or right. It's a horizontal translation determined by the value C/B in the general form.
Why are sine and cosine functions called periodic functions?
Because their graphs repeat their pattern over regular intervals (periods).
How do sine and cosine functions relate to right triangles?
In a right triangle, sine is the ratio of the opposite side to the hypotenuse, and cosine is the ratio of the adjacent side to the hypotenuse.