Graph y=sin(-2x)
Problem
Solution
Identify the parent function and its properties. The parent function is
y=sin(x) which has a period of2*π an amplitude of1 and passes through the origin(0,0) Apply the odd function property of the sine function. Since
sin(−θ)=−sin(θ) the equationy=sin(−2*x) can be rewritten asy=−sin(2*x) Determine the amplitude. The coefficient of the sine function is
−1 so the amplitude is|−1|=1 This means the graph oscillates betweeny=1 andy=−1 Calculate the period. The coefficient of
x isB=2 The periodP is calculated using the formulaP=(2*π)/|B|
Identify the phase shift and vertical shift. There are no horizontal or vertical translations, so the phase shift is
0 and the vertical shift is0 Find key points for one period
[0,π] Divide the period into four equal intervals of lengthπ/4
At
x=0 y=−sin(0)=0 At
x=π/4 y=−sin(π/2)=−1 At
x=π/2 y=−sin(π)=0 At
x=(3*π)/4 y=−sin((3*π)/2)=1 At
x=π y=−sin(2*π)=0
Sketch the graph by plotting these points and drawing a smooth wave. The graph is a sine wave reflected across the x-axis with a period of
π
Final Answer
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