Use the equation and given point to answer the questions below.
The equation of line a is y=12x−1, and it passes through point (6,2).
Line b is perpendicular to line a, and it passes through point (−6,2).
A: What is the slope of line b?
B: What is the y-intercept of line b?
Select two answers: one for A and one for B.
B: 14
B: 1
A: 1/2
A: −2
A: −1/2
B: 5
A: 2
B: -1
8 answers
Sorry line A is Y=1/2x-1
Recall that lines with slopes m1 and m2
are parallel if m1 = m2
are perpendicular if m1 * m2 = -1
so, since line A has slope 1/2, B has slope -2
Now for line B, you have a point (-6,2) and a slope (-2). Using the point-slope form, that makes B's equation
y-2 = -2(x+6)
Rearrange that into the slope-intercept form, and you have
y = -2x - 10
the y-intercept is seen to be -10
are parallel if m1 = m2
are perpendicular if m1 * m2 = -1
so, since line A has slope 1/2, B has slope -2
Now for line B, you have a point (-6,2) and a slope (-2). Using the point-slope form, that makes B's equation
y-2 = -2(x+6)
Rearrange that into the slope-intercept form, and you have
y = -2x - 10
the y-intercept is seen to be -10
A straight line in the form y = mx + b, has a slope of m and a y-intercept of b
so y = (1/2)x - 1 has a slope of 1/2 and a y-intercept of -1
Parallel lines have the same slope, so the slope of your new line is also 1/2
and it must be y = (1/2)x + b, but it passes through the new point (-6,2)
then 2 = (1/2)(-6) + b
2 = -3 + b
b = 5
so your 2nd line equation is y (1/2)x + 5
fit it all together to answer your question
so y = (1/2)x - 1 has a slope of 1/2 and a y-intercept of -1
Parallel lines have the same slope, so the slope of your new line is also 1/2
and it must be y = (1/2)x + b, but it passes through the new point (-6,2)
then 2 = (1/2)(-6) + b
2 = -3 + b
b = 5
so your 2nd line equation is y (1/2)x + 5
fit it all together to answer your question
argghhh, I read it as parallel
so go with oobleck's way
so go with oobleck's way
perpendicular lines have negative reciprocal slope. for line b slope then is -2. What is the y-intercept of line b? y=-2x+b and the point (−6,2) is one it, then
2=-2(-6)+b or b= 12+2 = 14
2=-2(-6)+b or b= 12+2 = 14
What is the answer?
a: -2
b: -10
b: -10
May the Fourth be with you