document.write( "Question 855915: write the equation of the parabola with vertex at the origin which satisfies the given condition:
\n" ); document.write( "a.axis on the y-axis and passes through (6,-3)
\n" ); document.write( "b.focus (0,4/3) and the equation of the directrix is y+4/3=0
\n" ); document.write( "c.directrix is x-4=0
\n" ); document.write( "d.focus at(0,2)
\n" ); document.write( "e. latus rectum is 6 units and the parabola opens to the left
\n" ); document.write( "f.focus on the x-axis and passes through (4,3)\r
\n" ); document.write( "\n" ); document.write( "ive tried answering but i dont know if i got the ryt answers . can anybody help me ? thank u so much in advance god bless
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Algebra.Com's Answer #515655 by KMST(5328)\"\" \"About 
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Equation of the parabola with vertex at the origin which satisfies the given condition:
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\n" ); document.write( "a. axis on the y-axis and passes through (6,-3)
\n" ); document.write( "Since the axis is on the y-axis, the equation is of the form \"y=ax%5E2\" .
\n" ); document.write( "We just have to find the constant \"a\" .
\n" ); document.write( "Since it passes through the point with \"x=3\" and \"y=-3\" ,
\n" ); document.write( "\"-3=a%2A6%5E2\"-->\"-3=36a\"-->\"-3%2F36=a\"-->\"a=-1%2F12\" .
\n" ); document.write( "So the equation is \"highlight%28y=-%281%2F12%29x%5E2%29\" or \"highlight%28y=-x%5E2%2F12%29\" .
\n" ); document.write( "
\n" ); document.write( "b. focus (0,4/3) and the equation of the directrix is y+4/3=0
\n" ); document.write( "That is twice as much information as needed.
\n" ); document.write( "We do not need both directrix and focus when we already have the vertex.
\n" ); document.write( "The focus and directrix must be at the same distance from the vertex,
\n" ); document.write( "so knowing that the vertex is at (0,0),
\n" ); document.write( "if the focus is at (0,4/3) the directrix equation had to be \"y=-4%2F3\"<-->\"y%2B4%2F3=0\" .
\n" ); document.write( "In a parabola with a focal distance of \"p\" the absolute value of the coefficient of the squared term is \"1%2F4p\" .
\n" ); document.write( "Since the focus has the same x-coordinate as the vertex, which is the origin,
\n" ); document.write( "and the focus has a positive y-coordinate,
\n" ); document.write( "the rest of the parabola is also above the x-axis.
\n" ); document.write( "So the coefficient is positive, and the equation is
\n" ); document.write( "\"y=%281%2F%284%2A%284%2F3%29%29%29x%5E2\"-->\"highlight%28y=%283%2F16%29x%5E2%29\" .
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\n" ); document.write( "c. directrix is x-4=0
\n" ); document.write( "\"x-4=0\"<-->\"x=4\" , meaning that the focal distance is \"p=4\" ,
\n" ); document.write( "and that the directrix is to the right of the vertex (the origin).
\n" ); document.write( "That means that the focus and the parabola (except for the vertex) are to the left of the y-axis.
\n" ); document.write( "Then the equation must be
\n" ); document.write( "\"x=-%281%2F4p%29y%5E2\"-->\"x=-%281%2F%284%2A4%29%29y%5E2\"-->\"highlight%28x=-%281%2F16%29y%5E2%29\" .
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\n" ); document.write( "d. focus at(0,2)
\n" ); document.write( "That means the focal distance is \"p=2\" and the focus is above the (0,0) vertex.
\n" ); document.write( "The equation of the parabola is
\n" ); document.write( "\"y=1%2F%284%2A2%29x%5E2\"-->\"highlight%28y=%281%2F8%29x%5E2%29\" .
\n" ); document.write( "
\n" ); document.write( "e. latus rectum is 6 units and the parabola opens to the left.
\n" ); document.write( "With the vertex at the origin and the parabola opening to the left, the equation is
\n" ); document.write( "\"x=ay%5E2\" with a negative coefficient, \"a%3C0\" .
\n" ); document.write( "with the focal distance represented by \"p\" , the latus rectum length is \"4p\" and the absolute value of the coefficient \"a\" is \"1%2F4p\" , the reciprocal of the latus rectum length.
\n" ); document.write( "So the equation is
\n" ); document.write( "\"highlight%28x=-%281%2F6%29y%5E2%29\"
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