What is the slope of the line passing through the point (4, −2) and perpendicular to the line y = 4x + 2? Write your answer as a fraction.

Question

jdoe0001 · Answer

what's the slope of => y = 4x + 2 ?

anonymous · Answer

?

jdoe0001 · Answer

http://www.algebra-class.com/image-files/slope-formula-1.gif

anonymous · Answer

oh yeah so what am i suppose to do with that.

jdoe0001 · Answer

get the slope of that equation first :)

anonymous · Answer

can I have the slope equation please.

jdoe0001 · Answer

$\bf m=\frac{y_2-y_1}{x_2-x_1}$

but you don't have 2 points on this 1st equation, you only have the equation

jdoe0001 · Answer

so you'd need to get it from the equation =>  y = 4x + 2

anonymous · Answer

but what am I suppose to do when they only give me one set points

jdoe0001 · Answer

we'll get there, but firstly we know this  -> y = 4x + 2  <- line is perpendicular to the other at (4, -2)
so, let's get the slope for this one 1st, so we can see if we can find the other :)

anonymous · Answer

???

jdoe0001 · Answer

http://www.algebra-class.com/image-files/slope-formula-1.gif can you find the slope from ^ picture?

anonymous · Answer

Im really unsure

jdoe0001 · Answer

y  = ax  + b
 y = 4x + 2
$ y = \color{red}{4}x + 2$
see it now?

anonymous · Answer

To find the slope of a line when you're given the equation of the perpendicular line, you take the slope, turn it upside down, then change the sign. So y = 4x + 2 has a slope of 4 --> turn it upside down = 1/4, change the sign --> -1/4. Therefore the slope of the second line is -1/4.

jdoe0001 · Answer

yes