document.write( "Question 1169709: for each of the following, give the amplitude, the period, and describe any vertical or horizontal shifts away from the origin(i.e. from the standard parent graph)\r
\n" ); document.write( "\n" ); document.write( "2a f(x) = -2sin[3(x-pi/2)] + 4\r
\n" ); document.write( "\n" ); document.write( "b. f(x) = -cos(2x -pi/4) -3\r
\n" ); document.write( "\n" ); document.write( "c. f(x) = 2tan(x/3) -1\r
\n" ); document.write( "\n" ); document.write( "d. f(x) = -sec(pi- 5x)
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Algebra.Com's Answer #794561 by ikleyn(52786)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "for each of the following, give the amplitude, the period, and describe any vertical or horizontal shifts
\n" ); document.write( "away from the origin(i.e. from the standard parent graph)
\n" ); document.write( "2a f(x) = -2sin[3(x-pi/2)] + 4
\n" ); document.write( "b. f(x) = -cos(2x -pi/4) -3
\n" ); document.write( "c. f(x) = 2tan(x/3) -1
\n" ); document.write( "d. f(x) = -sec(pi- 5x)
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\n" ); document.write( "\n" ); document.write( "            The analysis given by @MathLover1,  has  ERRORS,  that are extremely dangerous for a beginning student.\r
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\n" ); document.write( "\n" ); document.write( "            Therefore,  I came to  FIX  her errors and to bring a  CORRECT  ANALYSIS  with detailed explanations.\r
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document.write( "f(x) = -2sin[3(x-pi/2)] + 4.\r\n" );
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document.write( "It is obvious that the amplitude is |-2| = 2 and that the period is \"2pi%2F3\";  vertical shift is 4 units up.\r\n" );
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document.write( "For the further analysis, especially for the accurate analysis of the horizontal shift, you MUST write \r\n" );
document.write( "the given function with the POSITIVE leading factor (amplitude).\r\n" );
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document.write( "    // If you do not make it (as @MathLover1 NEGLECTS do it at every her attempt), you analysis INEVITABLY will be ERRONEOUS. //\r\n" );
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document.write( "So I write equivalent transformations \r\n" );
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document.write( "    f(x) = \"-2sin%283%28x-pi%2F2%29%29+%2B+4\" = \"-2sin%283x-3pi%2F2%29+%2B+4\" = \r\n" );
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document.write( "                I want to make the leading coefficient positive. For it, I continue\r\n" );
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document.write( "         = \"2sin%283x-3pi%2F2+%2B+pi%29+%2B+4\"    (I change the leading sign by adding \"pi\" to the sine argument, and then continue further)\r\n" );
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document.write( "         = \"2sin%283x+-+pi%2F2%29+%2B+4\" = \"2sin%283%2A%28x-pi%2F6%29%29+%2B+4\".\r\n" );
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document.write( "Now, having written the sine function in standard CANONIC form with the positive leading coefficient, \r\n" );
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document.write( "     I can make the standard analysis for the shift,  and I can safely conclude that the horizontal shift is  \"pi%2F6\"  units to the right.\r\n" );
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document.write( "Now look into the plot below, which CONFIRMS my analysis.\r\n" );
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document.write( "    \r\n" );
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document.write( "    Plot y = \"-2sin%283%28x-pi%2F2%29%29+%2B+4\" (the given function, red), \r\n" );
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document.write( "          and  y = sin(3x)         (the parent function for the shift analysis, green)\r\n" );
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document.write( "Notice that, when we compare the shift, our reference parent function for the comparison is y = sin(3x), shown by green in my plot.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Case (b) \r
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document.write( "f(x) = -cos(2x -pi/4) -3.\r\n" );
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document.write( "It is obvious that the amplitude is |-1| = 1 and that the period is \"2pi%2F2\" = \"pi\";  vertical shift is 3 units down.\r\n" );
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document.write( "For the further analysis, especially for the accurate analysis of the horizontal shift, you MUST write \r\n" );
document.write( "the given function with the POSITIVE leading factor (amplitude).\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    // If you do not make it (as @MathLover1 NEGLECTS do it at every her attempt), you analysis INEVITABLY will be ERRONEOUS. //\r\n" );
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document.write( "\r\n" );
document.write( "So I write equivalent transformations \r\n" );
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document.write( "    f(x) = \"-cos%282x-pi%2F4%29+-+3\" = \"-cos%282x-pi%2F4%29+-+3\" = \r\n" );
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document.write( "                I want to make the leading coefficient positive. For it, I continue\r\n" );
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document.write( "         = \"cos%282x-pi%2F4+%2B+pi%29+-+3\"    (I change the leading sign by adding \"pi\" to the cosine argument, and then continue further)\r\n" );
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document.write( "         = \"cos%282x+%2B+3pi%2F4%29+-+3\" = \"cos%282%2A%28x%2B%283pi%2F8%29%29%29+-+3\".\r\n" );
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document.write( "Now, having written the sine function in CANONIC form with the positive leading coefficient, \r\n" );
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document.write( "     I can make the standard analysis for the shift,  and I can safely conclude that the horizontal shift is  \"3pi%2F8\"  units to the left.\r\n" );
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document.write( "Now look into the plot below, which CONFIRMS my analysis.\r\n" );
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document.write( "    \r\n" );
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document.write( "    Plot y = \"-cos%282x+-pi%2F4%29+-3\" (the given function, red), \r\n" );
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document.write( "          and  y = cos(2x)         (the parent function for the shift analysis, green)\r\n" );
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document.write( "Notice that, when we compare the shift, our reference parent function for the comparison is y = cos(2x), shown by green in my plot.\r\n" );
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document.write( "f(x) = -sec(pi-5x).\r\n" );
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document.write( "In this case, there is NO amplitude. Obviously, the period is \"2pi%2F5\";  there is NO vertical shift.\r\n" );
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document.write( "\r\n" );
document.write( "For the further analysis, especially for the accurate analysis of the horizontal shift, you MUST write \r\n" );
document.write( "the given function with the POSITIVE leading factor.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "So I write equivalent transformations \r\n" );
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document.write( "    f(x) = \"-sec%28pi-5x%29\" = \r\n" );
document.write( "\r\n" );
document.write( "                I want to make the leading coefficient positive. For it, I change \r\n" );
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document.write( "                the leading sign by subtracting \"pi\" to the sec argument, and then continue further\r\n" );
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document.write( "         = \"sec%28pi+-+5x+-+pi%29\" = \"sec%28-5x%29\" = use the fact that sec is an EVEN function = \"sec%285x%29\".\r\n" );
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document.write( "Now, having written the sec function in CANONIC form with the positive leading coefficient, \r\n" );
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document.write( "     I can make the standard analysis for the shift,  and I can safely conclude that the horizontal shift is  0  (zero, ZERO) in this case.\r\n" );
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document.write( "\r\n" );
document.write( "Now look into the plot below, which CONFIRMS my analysis.\r\n" );
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document.write( "    \r\n" );
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document.write( "    Plot y = \"-sec%28pi-5x%29\" (the given function, red), \r\n" );
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document.write( "          and  y = sec(5x) + 0.2         (the parent function for the shift analysis, green)\r\n" );
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document.write( "Notice that, when we compare the shift, our reference parent function for the comparison is y = sec(5x), shown by green in my plot.\r\n" );
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document.write( "To make two plots distinguishable, I added 0.2 to the reference function // othewise, the plot are identical and the difference is not seen.\r\n" );
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\n" ); document.write( "\n" ); document.write( "At this point, my solution is COMPLETED.\r
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\n" ); document.write( "\n" ); document.write( "I hope that the reader sees now all errors of the solution by @MathLover1.\r
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\n" ); document.write( "\n" ); document.write( "She really made all possible and typical errors in her analysis.\r
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\n" ); document.write( "\n" ); document.write( "I really glad that I had the opportunity to fix all these errors and to teach the reader TO AVOID them.\r
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