document.write( "Question 81747: would someone help me to figure out how to find the second part of this problem and graph it please. Thanks\r
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document.write( "Given f(x)=-x-4, find f(a-3) \n" );
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Algebra.Com's Answer #58563 by bucky(2189) ![]() You can put this solution on YOUR website! Given f(x)=-x-4, find f(a-3) \n" ); document.write( ". \n" ); document.write( "f(a-3) tells you to replace x with the quantity (a-3). When you do that replacement, \n" ); document.write( "the original equation for f(x) becomes: \n" ); document.write( ". \n" ); document.write( "f(a-3) = -(a-3) - 4 \n" ); document.write( ". \n" ); document.write( "When you remove the parentheses on the right side, the minus sign in front of the parentheses \n" ); document.write( "require you to change the signs of all the terms in the parentheses. Applying this rule \n" ); document.write( "changes the equation to: \n" ); document.write( ". \n" ); document.write( "f(a-3) = -a + 3 -4 \n" ); document.write( ". \n" ); document.write( "Finally, simplify by combining the +3 and -4 to get: \n" ); document.write( ". \n" ); document.write( "f(a-3) = -a - 1 \n" ); document.write( ". \n" ); document.write( "To graph this equation, replace f(a-3) by y and you have: \n" ); document.write( ". \n" ); document.write( "y = -a - 1 \n" ); document.write( ". \n" ); document.write( "Call the vertical axis the y-axis and the horizontal axis the a-axis. \n" ); document.write( ". \n" ); document.write( "The equation y = -a - 1 is in the slope intercept form. If you set a equal to zero, the \n" ); document.write( "equation reduces to y = -1. This tells you that the point (0, -1) is on the graph. \n" ); document.write( "But this point identifies the value where the graph intersects the y-axis. \n" ); document.write( ". \n" ); document.write( "You can also set y equal to zero, and when you do that the equation becomes: \n" ); document.write( ". \n" ); document.write( "0 = -a - 1 \n" ); document.write( ". \n" ); document.write( "Add +a to both sides to eliminate the -a on the right side, and the equation changes to: \n" ); document.write( ". \n" ); document.write( "a = -1 \n" ); document.write( ". \n" ); document.write( "This tells you that when y = 0 then a = -1 so the point (-1, 0) is on the graph, and this \n" ); document.write( "point is on the a-axis at -1. \n" ); document.write( ". \n" ); document.write( "You now have two points on the graph. If you plot these two points, you can then use a \n" ); document.write( "straight edge to extend a line through them. Note that from the slope intercept form of \n" ); document.write( "the equation [y = -a -1] the slope is the multiplier of the \"a\" term. In this case that \n" ); document.write( "multiplier is -1. So the graph you have created has a slope of -1 and you can check \n" ); document.write( "your graphed line to make sure that for any point on the line, if you move horizontally \n" ); document.write( "1 unit from that point and then move 1 unit down you should be back on the graphed line. \n" ); document.write( ". \n" ); document.write( "When you get done, you should have a graph that looks like this except the label on the \n" ); document.write( "horizontal axis should be \"a\" instead of \"x\": \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Hope this helps you to understand the problem a little better. \n" ); document.write( ". \n" ); document.write( " |