Question

Which set of parametric equations describes a line that passes through the points (0,0) and (4,8) ?

A) x=t , y=2t
B) x=2t , y=3t
C) x=2t , y=t
D) x=4t , y=2t

Answer 1

The correct option is A)

Explanation:

To find the correct equation we first need to calculate the angular coefficient for the line, with the formula below:

m = (y2 - y1)/(x2 - x1)

m = (8 - 0)/(4 - 0) = 8/4 = 2

Using that we can apply to the equation of the line:

y = m*x + c

Since the line pass through (0,0) c must be equal to 0, so:

y = m*x

y = 2*x

So x must be:

x = t.