JSX GRAPH
Use the two dots to move the line to get the negative slope
board = JXG.JSXGraph.initBoard("jsxwoko", {boundingbox:[-10,30,30,-10],axis:true, showNavigation:false, showCopyright:false, keepaspectratio: false, axis:true, pan: {enabled: false, needTwoFingers: false, needShift: false},zoom: { wheel: false, needShift: false, pinchHorizontal:false, pinchVertical: false} });board.resizeContainer(300, 300); var pQ21 = board.create("point", [-8.5, 4], {visible:true, size: 6,name:""}); var pQ22 = board.create("point", [-8.5, -4],{visible:true, size: 6,name:""}); lQ7 = board.create("line", [pQ21, pQ22],{visible:true, size: 10});
Preview
Check