document.write( "Question 993370: A javelin is thrown from a height of 2m above the ground.
\n" ); document.write( "It lands 60 meters away. The path of the javelin can be represented by the equation $\"+y=ax%5E2%2Bbx%2Bc+\"$ \r
\n" ); document.write( "\n" ); document.write( "a) What does x and y represent in this situation?
\n" ); document.write( "b)If it is known that the point (10,15) lies on the path given by the equation $\"+y=ax%5E2%2Bbx%2Bc+\"$ , use algebra and all the information given in a) and b) to show
\n" ); document.write( "that:\r
\n" ); document.write( "\n" ); document.write( " $\"+a=-2%2F75+\"$ , $\"+b=47%2F30+\"$ and c = 2\r
\n" ); document.write( "\n" ); document.write( "c)Hence find the height of the javelin after travelling 20m horizontally\r
\n" ); document.write( "\n" ); document.write( "For a) Does y represent the height of the javelin, and x represent the horizontal distance traveled? \r
\n" ); document.write( "\n" ); document.write( "For b) I have no idea :c\r
\n" ); document.write( "\n" ); document.write( "For c) Really stuck!\r
\n" ); document.write( "\n" ); document.write( "It would be very helpful if you could draw up a graph too!! Thanks for help!! \n" ); document.write( "

Algebra.Com's Answer #612721 by MathLover1(20849) $\"\"$ $\"About$

You can put this solution on YOUR website!
a) What does $\"x\"$ and $\"y\"$ represent in this situation?\r
\n" ); document.write( "\n" ); document.write( " $\"y\"$ represent height (dependent variable,depends on how $\"x\"$ changes )
\n" ); document.write( " $\"x\"$ represent the path (dependent variable,it is a variable that stands alone and isn't changed by the other variables you are trying to measure )\r
\n" ); document.write( "\n" ); document.write( "b)
\n" ); document.write( "If it is known that the point ( $\"10\"$ , $\"15\"$ ) lies on the path given by the equation $\"y=ax%5E2%2Bbx%2Bc\"$ , use algebra and all the information given in a) and b) to show that:
\n" ); document.write( " $\"a+=+-2%2F75\"$ , $\"b+=+47%2F30\"$ and $\"c+=+2\"$ \r
\n" ); document.write( "\n" ); document.write( "if the point ( $\"x\"$ , $\"y\"$ )=( $\"10\"$ , $\"15\"$ ), we have\r
\n" ); document.write( "\n" ); document.write( " $\"y=ax%5E2%2Bbx%2Bc\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"15=100a%2B10b%2Bc\"$ ..............eq.1\r
\n" ); document.write( "\n" ); document.write( " if $\"a+=+-2%2F75\"$ , $\"b+=+47%2F30\"$ and $\"c+=+2\"$ , we have equation like this:\r
\n" ); document.write( "\n" ); document.write( " $\"y=-%282%2F75%29x%5E2%2B%2847%2F30%29x%2B2+\"$ ...now,show that $\"y=15\"$ when $\"x=10\"$ \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"y=+-%282%2F75%2910%5E2%2B%2847%2F30%2910%2B2+\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=+-%282%2F75%29100%2B%2847%2F30%2910%2B2+\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=+-%282%2F15%2920%2B%2847%2F3%29%2B2+\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=+-%2840%2F15%29%2B%2847%2F3%29%2B2+\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=+-%2840%2F15%29%2B%28%2847%2A5%29%2F15%29%2B%282%2A15%29%2F15+\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=+%28-40%2B235%2B30%29%2F15\"$
\n" ); document.write( "
\n" ); document.write( " $\"y=+225%2F15\"$
\n" ); document.write( "
\n" ); document.write( " $\"y=+15+\"$ \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "c)\r
\n" ); document.write( "\n" ); document.write( "Hence find the height $\"y\"$ of the javelin after traveling $\"x=20m\"$ horizontally\r
\n" ); document.write( "\n" ); document.write( " $\"y=+-%282%2F75%29x%5E2%2B%2847%2F30%29x%2B2\"$
\n" ); document.write( "
\n" ); document.write( " $\"y=+-%282%2F75%2920%5E2%2B%2847%2F30%2920%2B2+\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=+-%282%2F75%29400%2B%2847%2A20%29%2F30%2B2\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=+-%28800%2F75%29%2B%28940%29%2F30%2B2\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=+-%28160%2F15%29%2B%28470%2F15%29%2B30%2F15\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=+%28470-160%2B30%29%2F15%29\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=+%28500-160%29%2F15%29\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=+340%2F15%29\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=22.66666666666667\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=22.7\"$ \r
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