Question

Find the value of p when the line through the points (2 2) and (5,7) is perpendicular to the line 3x+py-9=0

Answer 1

i ) Slope ( m ) of a line passing through

the points A( x1 , y1 ) = ( 2 , 2 ) and

B( x2 , y2 ) = ( 5 , 7 ) is

m1 = ( y2 - y1 )/( x2 - x1 )

m1 = ( 7 - 2 )/( 5 - 2 )

m1 = 5/3 ----( 1 )

ii ) slope of a line perpendicular to AB

line ( m2 ) = - 3/5 ----( 2 )

iii ) Slope of a line 3x + py - 9 = 0

slope = - 3/p ---( 3 )

( 2 ) and ( 3 ) shows slope of a same line.

( 2 ) = ( 3 )

- 3/5 = - 3/p

p = 5

I hope this helps you