Question

3. Write the equation of a line that is perpendicular to y= 1/3 + 3 and goes through the point (1-2).

Answer 1

y=-3x+1.

Explanation:

if the given line is y= 1/3 x+3 (slope-interception form), then

1) the slope of the given line is 1/3, then the slope of the required line is (-3), and the required equation is: y= -3x+i, where i - unknown interception;

2) in order to calculate the unknown interception, it is needed to substitute the given coordinates of the point (1;-2) into the required equation:

-2=-3*1+i, then i=1;

3) finally, if the slope= -3, interception=1, then the required equation of the line is:

y= -3x+1.