document.write( "Question 1158869: What is a y intercept and what purpose does it serve? (I am a not so mathematical Dad trying to help a challenged child)
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Algebra.Com's Answer #781850 by Cromlix(4381)\"\" \"About 
You can put this solution on YOUR website!
Hi there,
\n" ); document.write( "The equation of a line is y = mx + c
\n" ); document.write( "m = gradient or slope
\n" ); document.write( "c = the line's y intercept \r
\n" ); document.write( "\n" ); document.write( "Knowing the line's y intercept allows, with the x intercept, to work out the gradient or slope.
\n" ); document.write( "e.g. y = 4x + 8
\n" ); document.write( "To find where the line cuts the x axis make y = 0
\n" ); document.write( "0 = 4x + 8
\n" ); document.write( "4x = -8
\n" ); document.write( "x = -2 Cuts x axis at (-2, 0)
\n" ); document.write( "To find where line cuts the y axis make x = 0
\n" ); document.write( "y = 4x + 8
\n" ); document.write( "y = 4(0) + 8
\n" ); document.write( "y = 8 cuts y axis at (0, 8)
\n" ); document.write( "To find the gradient use y2 - y1/x2 - x1
\n" ); document.write( "Using the example y = 4x + 8, the y intercept (0, 8) (x1, y1) and the x intercept (-2, 0) (x2, y2)
\n" ); document.write( "y2 - y1/x2 - x1 = 0 - 8/-2 - 0 = -8/-2 = 4 The gradient (slope) in y = 4x + 8
\n" ); document.write( "Hope this helps, mate. :-) \n" ); document.write( "
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