Find the equation of the line: Passing through the origin and parallel

1.	Find the equation of the line: Passing through the origin and parallel to AB, where A is (2,4) and B is (1,7).
Answer» Given, A (2, 4) and B (1, 7) Slope of AB = \(\frac {7-4}{1-2} =\)-3 1-2 Since the required line is parallel to line AB, slope of required line (m) = slope of AB ∴ m = – 3 and the required line passes through the origin. Equation of the line having slope m and passing through origin (0, 0) is y = mx. ∴ The equation of the required line is y = – 3x

Find the equation of the line: Passing through the origin and parallel to AB, where A is (2,4) and B is (1,7).

Answer»

Given, A (2, 4) and B (1, 7)

Slope of AB = \(\frac {7-4}{1-2} =\)-3 1-2

Since the required line is parallel to line AB, slope of required line (m) = slope of AB

∴ m = – 3 and the required line passes through the origin.

Equation of the line having slope m and passing through origin (0, 0) is y = mx.

∴ The equation of the required line is y = – 3x