Question

if 2y - 4x = 5 and 4x + ky + 3 = 0 are perpendicular to each other,find the value of k

Answer 1

@campbell_st

Answer 2

M1 X M2 = -1

Answer 3

ok... so the line

2y - 4x = 5

can you write it in slope intercept form y = mx + b..?

Answer 4

M1 = 2??

Answer 5

well

ok... so what is the negative reciprocal of 2...?

Answer 6

-2

Answer 7

reciprocal

Answer 8

well thats the negative... reciprocal means to turn it upside down

so 2/1 becomes 1/2

so that means the slope of the perpendicular line is -1/2

now take the like

4x + ky + 3 = 0

can you write this in slope intercept form..?

Answer 9

as a start

ky = -4x - 3

what do you think the slope of this line is..?

Answer 10

-4/k

Answer 11

for the line to be perpendicular m1 x m2 = -1

Answer 12

k= 8