Is anyone good at Point-Slope form, and stuff like that? With perpendicular lines?

Question

solomonzelman · Answer

$$\huge {Shoot!}$$

anonymous · Answer

Ok, can you help me solve this? 	Write the equation of the line that is perpendicular to the line y = 2x + 2 and passes through the point (6, 3).
 		
	y = 2x + 6
	y = −one halfx + 3
	y = −one halfx + 6
	y = 2x + 3

solomonzelman · Answer

You have y = 2x + 6
the perpendicular slope for  'm'  is going to be  -1/m, this is always true.
So for 2, it is   -1/2.
now rewrite it,
 y = -1/2x +b
we know the slope of the perpendicular equation, but we have to find the y-intercept
plug your point in
 (6, 3)
 y = -1/2x +b  --->  (3) = -1/2(6) +b  ----> 3=-3+b
add 3 to both sides.
6=b
so you have
 y = -1/2x + 6
as your final answer.

solomonzelman · Answer

@Niall, $$\huge {Good?}$$

anonymous · Answer

Yeah I think I get it.

I have another more confusing one, can you help me with it too?

solomonzelman · Answer

I can try, I am not good at math.

anonymous · Answer

Write the equation of the line that is perpendicular to the line 3x + y = 7 and passes through the point (6, −1).
 	
	y = one thirdx − 3
	y = one thirdx + 17
	y = −3x − 3
	y = −3x + 17

solomonzelman · Answer

3x + y = 7  --->  into slope intercept form  ---> y = -3x+7
You have y = -3x + 7
the perpendicular slope for  'm'  is going to be  -1/m, this is always true.
So for -3, it is   1/3.
now rewrite it,
 y = 1/3x +b
we know the slope of the perpendicular equation, but we have to find the y-intercept
plug your point in
(6, −1)
 y = 1/3x +b  --->  (-1) = 1/3(6) +b  ----> -1=2+b
subtract 2 from both sides.
-3=b
so you have
 y = 1/3x - 3
as your final answer.

solomonzelman · Answer

See it is the SAME THING!

anonymous · Answer

Ohh ok. I'll post another 1, but don't give me the answer. I'm gonna try to solve it first. Then tell me if its right please. :)

anonymous · Answer

Write the equation of the line that is parallel to the line 4x − 3y = −12 and passes through the point (−3, 4).
 	
	y = four thirdsx + 8
	y = four thirdsx + 3
	y = −three fourthsx + 8
	y = −three fourthsx + 3

anonymous · Answer

Ok, is it y = 4/3x + 8?

solomonzelman · Answer

can't be right, it is wrong.

anonymous · Answer

Dang, do you know what it is?

solomonzelman · Answer

yes, I can show you,
you got the right slope, but not the y intercept.
y = 4/3x + b
plug in  (−3, 4)   into  this.

And you were right!
SORRY!

solomonzelman · Answer

I miscalculated, you were correct!

anonymous · Answer

Yayyyy! :P Ok, thanks a lot for the help! :)

solomonzelman · Answer

$\huge {ANYTIME!}$


$\huge {(•‿•)}$