Maths AS help!!

hi i need to understand how to do this question:

The lines y = 5x - 6 and 10x + cy = 8 are perpendicular, find the value of c?

i really need help!!!

THANKS

Reply 1

KAISER_MOLE

ArsenalTFX

hi i need to understand how to do this question:

The lines y = 5x - 6 and 10x + cy = 8 are perpendicular, find the value of c?

i really need help!!!

THANKS

For the lines to be perpendicular, the coefficient of x in lines have to be m and -1/m respectively

=> in equation 2, coeff of x= -1/5

=> 10x-8 =-cy

=> 10x-8 / -c = y
=> 10/-c = -1/5

=> c=50

Reply 2

steve2005

ArsenalTFX

hi i need to understand how to do this question:

The lines y = 5x - 6 and 10x + cy = 8 are perpendicular, find the value of c?

i really need help!!!

THANKS

here is solution and a graph