document.write( "Question 401463: How do I graph points (i.e (0,0), (3,-2), (4,-5)) on a coordinate plane? \n" ); document.write( "
Algebra.Com's Answer #285062 by lwsshak3(11628)![]() ![]() ![]() You can put this solution on YOUR website! How do I graph points (i.e (0,0), (3,-2), (4,-5)) on a coordinate plane?\r \n" ); document.write( "\n" ); document.write( "..\r \n" ); document.write( "\n" ); document.write( "Remember the form of a quadratic equation: \n" ); document.write( "y=ax^2+bx+c \n" ); document.write( "We do not know whether this is a quadratic equation, but we can try to find a, b, and c, then graph it to find out if it is a quadratic equation.\r \n" ); document.write( "\n" ); document.write( "for coordinates(0,0), 0=a(0^2)+b*0+c \n" ); document.write( "0=c \n" ); document.write( "c=0 \n" ); document.write( "for coordinates(3,-2), -2=a(3^2)+3b+c \n" ); document.write( "-2=9a+3b+c \n" ); document.write( "9a+3b+c=-2 \n" ); document.write( "for coordinates(4,-5), -5=a(4^2)+4b+c \n" ); document.write( "-5=a(16)+4b+c \n" ); document.write( "16a+4b+c=-5\r \n" ); document.write( "\n" ); document.write( "we now have 3 equations with 3 unknowns, but c=0, so we only have two of the unknowns, a and b, to solve\r \n" ); document.write( "\n" ); document.write( "9a+3b=-2 \n" ); document.write( "16a+4b=-5 \n" ); document.write( "multiply first equation by 4, and second equation by -3 \n" ); document.write( "36a+12b=-8 \n" ); document.write( "-48a-12b=+15 \n" ); document.write( "-12a=7 \n" ); document.write( "a=-7/12 \n" ); document.write( "b=(-2-9a)/3 \n" ); document.write( " =((-8/4-(9*-7/12))/3 \n" ); document.write( " =(-8/4+21/4)/3 \n" ); document.write( " =(13/4)/3 \n" ); document.write( "b=13/12 \n" ); document.write( "we now have an equation which appears to be a parabola. \n" ); document.write( "f(x)=-(7/12)x^2+(13/12)x+0\r \n" ); document.write( "\n" ); document.write( "see the graph below: note the 3 given coordinates,(0,0),(3,-2),and (4,-5) on the curve \r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |