Question

What is the equation of the line that is perpendicular to y = 2x – 4 and has a y-intercept of –2?

Answer 1

slope intercept form of line :-
\(y = mx + b\)

Answer 2

\(m\) = slope
\(b\) = intercept

Answer 3

you already have the intercept of perpendicular line :
\(b = -2\)

you need to find \(m\)

Answer 4

you need the negative reciprocal of the given slope

Answer 5

I still dont get it :/

Answer 6

what is the slope in the equation y = 2x - 4 ?

Answer 7

In y = mx + b form, like ganshie said, the m position is the slope and the b position is the y intercept. So what is in the m position ?

Answer 8

do you know ?

Answer 9

y = mx + b (the m position is the slope)
y = 2x - 4....what is in the m position ?

Answer 10

ok......the 2 is in the m position. Can you see that now ?

Answer 11

2 is the slope of the given equation. But we need a perpendicular line, so we need the negative reciprocal of that slope. All that means is " flip " the slope and change the sign.
The negative reciprocal of 2, or 2/1, is -1/2 (see how I flipped the slope and changed the sign).

We need to use -1/2 as our slope and -2 as our y intercept.
Remember, in y = mx + b form, the m is the slope and the b is the y intercept.
So the perpendicular line would be : y = -1/2x - 2

Answer 12

perpendicular to y = 2x – 4 and has a y-intercept of –2:
Given equation of line is 2x-y-4=0;
so, equation of line perpendicular to it will be x+2y+k=0.....(I)
if y-intercept is -3, then line passes through (0,-2),
on putting this value of x and y in (I),
k=4;
therefore, equation of line is [x+2y+4=0]