document.write( "Question 406287: Find the vertex, focus, and directrix without completing the square, and deteremine opens upward or downward.
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document.write( "y=-1/2x sq -3x +2
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document.write( "I've determined it will open downward, but am confused on how to get the rest of the answers.... \n" );
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Algebra.Com's Answer #286866 by lwsshak3(11628)![]() ![]() ![]() You can put this solution on YOUR website! y=-1/2x sq -3x +2\r \n" ); document.write( "\n" ); document.write( "..\r \n" ); document.write( "\n" ); document.write( "If you do not complete the square to solve, you can use another method using the formula, x-coordinate of the vertex=-b/2a. \n" ); document.write( "In the given equation, a=-(1/2), b=-3 \n" ); document.write( "x=-(-3)/2(-1/2)=3/-1=-3 \n" ); document.write( "solving for y=-(1/2)(-3)^2 -3(-3) +2 \n" ); document.write( "y=-9/2+9+2=13/2 \n" ); document.write( "This is a parabola that opens downward. \n" ); document.write( "Coordinates of the vertex are (-3,13/2) \n" ); document.write( "Axis of symmetry, x=-3 \n" ); document.write( "Set x=0 to find the y-intercept=2 \n" ); document.write( "Set y=0 and solve for x-intercepts by factoring or by using the quadratic formula. \n" ); document.write( "x=[-(-3)+-sqrt(3^2-4(-1/2)(2)]2*(-1/2) \n" ); document.write( "x=(3+sqrt(13)/-1 or (3-sqrt(13)/-1 \n" ); document.write( "x=-6.6 or x=.61 \n" ); document.write( "see the graph below of the given equation \n" ); document.write( "..\r \n" ); document.write( "\n" ); document.write( " |