document.write( "Question 40036: for quadratic functions, sketch two parabolas showing all procedure (concavity, y-intercept, x-intercept, symmetric axis and vertex point)
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document.write( "a. y=2x^2-3x+1
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document.write( "b.y=-3x^2+2x+1 \n" );
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Algebra.Com's Answer #25471 by venugopalramana(3286)![]() ![]() You can put this solution on YOUR website! For quadratic functions, sketch two parabolas showing \n" ); document.write( "> all procedure(concavity, y-intercept, x-intercepts, \n" ); document.write( "> symmetric axis, and vertex point) \n" ); document.write( "> y=2x^2-3x+1...make x coefficient 1 and .complete square \n" ); document.write( "y=2{x^2-2*x*0.75+0.75^2}+1-2*0.75^2 \n" ); document.write( "=2(x-0.75)^2-0.125...so this will have a minimum at x=0.75...then y =-0.125...so \n" ); document.write( "1.vertex is(0.75,-0.125)...it is a minimum...so parabola has a trough \n" ); document.write( "at the bottom or convex down wards .....concave upwards. \n" ); document.write( "2.axis of symmetry is x-0.75=0....or x=0.75 \n" ); document.write( "3.when x =0....y=2*0.75^2-0.125=1...hence y intercept=1 \n" ); document.write( "4.when y=0....2(x-0.75)^2=0.125......so x is \n" ); document.write( "REAL...that is it has 2 x interceptS..that is it cutS x \n" ); document.write( "axis AT 2 PLACES \n" ); document.write( " \n" ); document.write( "5.as far as sketching goes , you can try that by \n" ); document.write( "1.draw x & y axes with a suitable scale. \n" ); document.write( "2.plot vertex at (0.75,1.125) \n" ); document.write( "3.draw axis of symmetry a vertical line at x=0.75 \n" ); document.write( "4.plot th y intercept at x=0 and y=2.25..that is curve cuts y axis at 2.25 \n" ); document.write( "5.sketch a symmetric graph from vertex upwards around the axis of \n" ); document.write( "symmetry of x=0.75\r \n" ); document.write( "\n" ); document.write( "> y=-3x^2+2x+1...same way as abov \n" ); document.write( "y=-3{x^2-2*x*(1/3)+(1/3)^2}+1+(1/3)^2 \n" ); document.write( "=(10/9)-3{x-(1/3)}^2 \n" ); document.write( "so.... \n" ); document.write( "1.vertex is(1/3,10/9)...it is a maximum...so parabola has a peak at \n" ); document.write( "the top or convex up wards .....concave downwards. \n" ); document.write( "2.axis of symmetry is x-1/3=0....or x=1/3 \n" ); document.write( "3.when x =0....y=10/9-3/9=7/9...hence y intercept=7/9 \n" ); document.write( "4.when y=0....3{x-(1/3)}^2=10/9........so x is real=(1/3)+ and - \n" ); document.write( "sqrt(10/27)...that is it has 2.. x intercepts..that is it cuts x axis \n" ); document.write( "at 2 places \n" ); document.write( " \n" ); document.write( "5.as far as sketching goes ,but you can try that by the same way as given above. \n" ); document.write( " |