document.write( "Question 165101: A baseball is hit at a point 3 ft above the ground at a velocity of 100ft/s and at an angle of 45 degrees with respect of the ground. The path of the baseball is given by the function f(x) = -0.0032x2 + x +3 where f(x) is the height of the baseball (in feet) and x is the horizontal distance from home plate (in feet). What's the maximum hieght reached by the baseball? \n" ); document.write( "
Algebra.Com's Answer #121685 by jim_thompson5910(35256)\"\" \"About 
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Remember, the max height occurs at the vertex. So if we find the y-coordinate of the vertex, we find the max height.\r
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\n" ); document.write( "\n" ); document.write( "Note: the same applies to the min height (if there exists a min height)\r
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\n" ); document.write( "\n" ); document.write( "In order to find the vertex, we first need to find the x-coordinate of the vertex.\r
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\n" ); document.write( "\n" ); document.write( "To find the x-coordinate of the vertex, use this formula: \"x=%28-b%29%2F%282a%29\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-b%29%2F%282a%29\" Start with the given formula.\r
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\n" ); document.write( "\n" ); document.write( "From \"y=-0.0032x%5E2%2Bx%2B3\", we can see that \"a=1\", \"b=1\", and \"c=3\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-%281%29%29%2F%282%28-0.0032%29%29\" Plug in \"a=-0.0032\" and \"b=1\".\r
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\n" ); document.write( "\n" ); document.write( "\"x=%28-1%29%2F%28-0.0064%29\" Multiply.\r
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\n" ); document.write( "\n" ); document.write( "\"x=156.25\" Divide\r
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\n" ); document.write( "\n" ); document.write( "So the x-coordinate of the vertex is \"x=156.25\".\r
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\n" ); document.write( "\n" ); document.write( "Now that we know the x-coordinate of the vertex, we can use it to find the y-coordinate of the vertex.\r
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\n" ); document.write( "\n" ); document.write( "\"y=-0.0032x%5E2%2Bx%2B3\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"y=-0.0032%28156.25%29%5E2%2B156.25%2B3\" Plug in \"x=156.25\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=-0.0032%2824414.0625%29%2B156.25%2B3\" Square \"156.25\" to get \"24414.0625\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=-78.125%2B156.25%2B3\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"y=81.125\" Combine like terms.\r
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\n" ); document.write( "\n" ); document.write( "So the y-coordinate of the vertex is \"y=81.125\".\r
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\n" ); document.write( "\n" ); document.write( "So the vertex is (156.25,81.125).\r
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\n" ); document.write( "\n" ); document.write( "Since the y-coordinate is \"y=81.125\", this means that the max height is 81.125 ft.
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