<!DOCTYPE html>
<html>
<body>
<canvas id="myCanvas" width="400" height="400" style="border:1px solid grey"></canvas>
<script>
const canvas = document.getElementById("myCanvas");
const ctx = canvas.getContext("2d");
ctx.fillStyle = "#FF0000";
canvas.height = canvas.width;
ctx.transform(1, 0, 0, -1, 0, canvas.height)
let xMax = canvas.height;
let slope = 1.2;
let intercept = 70;
ctx.moveTo(0, intercept);
ctx.lineTo(xMax, f(xMax));
ctx.strokeStyle = "black";
ctx.stroke();
function f(x) {
return x * slope + intercept;
}
</script>
</body>
</html>
