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Learn how to graph sine, cosine, tangent, cotangent, secant, and cosecant functions with step-by-step instructions and practical applications. Master different forms and understand amplitudes, periods, and phase shifts.
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Chapter 3Graphing Trigonometric Functions 3.1 Basic Graphics 3.2 Graphing y = k + A sin Bx and y = k +A cos Bx 3.3 Graphing y = k + A sin (Bx + C) and y = k +A cos (Bx + C) 3.4 Additional Applications 3.5 Graphing Combined Forms 3.6 Tangent, Cotangent, Secant, and Cosecant Functions Revisited
3.1 Basic Graphs • Graphs of y = sin x and y = cos x • Graphs of y = tan x and y = cot x • Graphs of y = csc x and y = sec x • Graphing with a graphing calculator
3.2 Graphing y= k + A sin Bx and y = k + A cos Bx • Graphing y = A sin x and y = A cos x • Graphing y = sin Bx and y = cos Bx • Graphing y = A sin Bx and y = A cos Bx • Graphing y= k + A sin Bx and y = k + A cos Bx • Applications
Comparing Amplitudes • Compare the graphs of y = 1/3 sin x and y = 3 sin x • The effect of A in y = A sin x is to increase or decrease the y values without affecting the x values.
Comparing Periods • Compare the graphs of y = sin 2x and y = sin ½ x The graph shows the change in the period.
Amplitude and Period For both y = A sin Bx and y = A cos Bx: Amplitude = |A| Period = 2p/B
Vertical Shift • y = -2 + 3 cos 2x, -p x 2p • Find the period, amplitude, and phase shift and then graph
Period and Frequency • For any periodic phenomenon, if P is the period and f is the frequency, P = 1/f.
3.3 Graphing y = k + A sin (Bx + C) and y = k + A cos (Bx + C) • Graphing y = A sin (Bx + C) and y = A cos (Bx + C) • Graphing y = k + A sin (Bx + C) and y = k + A cos (Bx + C) • Finding the equation for the graph of a simple harmonic motion
Finding Period and Phase Shift • y = A sin (Bx + C) and y = A cos (Bx + C) • These have the same general shape as y = A sin Bx and y = A cos Bx translated horizontally. • To find the translation: x = -C/B (phase shift) and x = -C/B + 2p/B
Phase shift and Period • Find the period and phase shift of y = sin(2x + p/2) • The period is p. • The phase shift is –p/4.
3.4 Additional Applications • Modeling electric current • Modeling light and other electromagnetic waves • Modeling water waves • Simple and damped harmonic motion: resonance
Alternating Current Generator • I = 35 sin (40pt – 10p) (current) • Amplitude = 35 • Phase shift: 40pt = 10p t = ¼ • Frequency = 1/Period = 20 Hz • Period = 1/20
Electromagnetic Waves • E = A sin 2p(vt – r/l) • t = time, r = distance from the source, l is the wavelength, v is the frequency
Water Waves • y = A sin 2p(f1t – r/l) • t = time, r = distance from the source, l is the wavelength, f1 is the frequency
Damped Harmonic Motion • Y = (1/t)sin (p/2)t, 1 t 8 • First, graph y = 1/t. • Then, graph y = sin(pt/2) keeping high and low points within the envelope.
3.6 Tangent, Cotangent, Secant, and Cosecant Functions Revisited • Graphing y = A tan (Bx + C) and y = cot (Bx + c) • Graphing y = A sec (Bx + C) and y = csc (Bx + c)
Graphing y = A tan (Bx + C) • Y = 3 tan (p/2(x) + p/4), -7/2 x 5/2 • Phase shift = -1/2 • Period = 2 • Asymptotes at -7/2, -3/2, ½, and 5/2
Graph of y = sec x • Graph y = 5 sec (1/2(x) + p) for -7p x 3p.
Graphing y = A csc(Bx + C) • Graph y = 2 csc (p/2(x) = p) for -2 < x < 10