document.write( "Question 1140741: Sinusoidal Functions
\n" ); document.write( "Without graphing, determine the amplitude, period, equation of the axis, phase shift, domain, and range of the function y=20 cos(9x-81°)-2
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Algebra.Com's Answer #761250 by greenestamps(13200)\"\" \"About 
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\n" ); document.write( "\"y+=+a%2Acos%28b%28x-c%29%29%2Bd\"

\n" ); document.write( "a is the amplitude
\n" ); document.write( "360/b degrees is the period
\n" ); document.write( "c is the positive phase shift (that is, x-45 means shift 45 degrees to the right; x+60 (= x-(-60)) means shift 60 degrees to the left)
\n" ); document.write( "d is the vertical shift

\n" ); document.write( "Put your function in that form by factoring out the coefficient of x:

\n" ); document.write( "\"y+=+20%2Acos%289%28x-9%29%29-2\"

\n" ); document.write( "amplitude: a = 20
\n" ); document.write( "period: 360/b = 360/9 = 40 degrees
\n" ); document.write( "phase shift: c = 9 degrees to the right
\n" ); document.write( "vertical shift: d = -2, which means the axis (center line) is y=-2
\n" ); document.write( "domain: all reals
\n" ); document.write( "range: plus or minus 20 from the center line of -2, so -22 to +18
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