Plot the function y = 2x-2. Does the graph of the function pass through point M (-20; -40)?
y = 2x – 2 is a linear function, the graph of a linear function is a straight line; to build a straight line, it is enough for us to know its two points; give 2 x values and find the corresponding y values;
x1 = 1; y1 = 2 * 1 – 2 = 2 – 2 = 0 – got the first point (1; 0);
x2 = 2; y2 = 2 * 2 – 2 = 4 – 2 = 2 – second point (2; 2).
Draw points in the coordinate plane and draw a straight line through them.
Let’s check if the straight line passes through the point M (- 20; – 40). To do this, you need to substitute the coordinates of the point x = – 20, y = – 40 into the equation of the straight line y = 2x – 2, and check whether the equality holds.
-40 = 2 * (- 20) – 2;
-40 = – 40 – 2;
-40 = – 42 – not true, so the graph does not pass through point M.