How would I find the y-intercept if given coordinates?

Question

I NEED HELP!!! I need to find the y-intercept of a line which passes through (1, 0) and is perpendicular to y = -3x -1.

Answer 1

since the slope of a line perpendicular to another one is the negative reciprocal, the slope of the line is 1/3.

You know that it passes through (1,0), while you want (0,y).

the slope of the new line is y=1/3x+b, where b is the y intercept.

using that, plug in 1 for x, 0 for y, because you know it has to pass through there.

this gives you 0=1/3+b, meaning b=-1/3.

the y intercept is -1/3

Answer 2

Well a good start is knowing the slope... the slope is the negative reciprocal of -3, therefore 1/3. Now use the points and plug it in the point-slope formula. The formula is y - y1( where your point should go) = m(slope) x (x- x1( your other point) after plugging in your points just distribute and bring x to the side where why is. Do not try to reduce! just send the x with its quantity over! hope i helped you somewhat ><