The equation of line CD is y = 3x - 3. Write an equation of a line perpendicular to line CD in slope-intercept form that contains point (3, 1). (5 points)

y = 3x + 0
y = -3x - 8
y = x + 2
y = - x + 0

Question

The equation of line CD is y = 3x - 3. Write an equation of a line perpendicular to line CD in slope-intercept form that contains point (3, 1). (5 points)

 	
	y = 3x + 0
	y = -3x - 8
	y =  x + 2
	y = -  x + 0

texaschic101 · Answer

you need to find the slope of the equation given. We do this because a perpendicular line will have a negative reciprocal slope. Do you know the slope of y = 3x - 3 ??

anonymous · Answer

no i just think its choice 1

texaschic101 · Answer

no...its not choice 1.  I can tell you right now, just by looking, that the answer does not match any of your answer choices. Are you sure they are written correctly ?

anonymous · Answer

thats what it says on my assignment

texaschic101 · Answer

the slope of the equation given is 3. A perpendicular line will have a negative reciprocal slope. All that means is " flip " the slope and change the sign. So the slope we need is gonna be -1/3....see how I flipped the slope and changed the sign.
Now use y = mx + b
slope(m) = -1/3
(3,1)...x = 3 and y = 1
now sub
y = mx + b
1 = -1/3(3) + b
1 = -1 + b
1 + 1 = b
2 = b

your perpendicular line would be : y = -1/3x + 2

texaschic101 · Answer

possibly choice C....if the -1/3 was in there

anonymous · Answer

thank you.. my school has a lot of errors so i will let them know

texaschic101 · Answer

glad to help :)