Question

What is the x-coordinate of the function below when the y-coordinate is 0?(0,5) (2,-5)

Answer 1

The equation of the function is assumed to be a straight line is of the form,

$y= mx+c$,  where  $m,c$

are the gradient and the y intercept respectively.

The gradient is computed using the formula for the gradient, i.e

$m=\frac{y_2-y_1}{x_2-x_1} = \frac{-5-5}{2-0} = -5$.

The equation of the line is,

$y= -5x+c\\=>5=-5(0)+c\\=> c= 5$

The equation of the function is ,

$y = -5x+5.$.

The value of the x-coordinate when the y coordinate is 0 is found as shown below.

$0=-5x+5\\=>x=1$.

so the x-coordinate is 1.