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Find the equation of the perpendicular from the point P(-1,-2) on the line

3x + 4y - 12 = 0. also find the coordinates of the foot of the perpendicular.



User Yemre
by
2.5k points

2 Answers

8 votes
8 votes

(44/25 , 42/25)

these are the points

User Taraz
by
3.1k points
20 votes
20 votes

eq :- 4x - 3y - 2 =0

and coordinates :- (44/25,42/25)

Step-by-step explanation:-

The given line is 3x + 4y - 12 = 0

=> 4y = -3x + 12 ....(i)

=> y = -3x/4 + 3,

therefore, the slope of the line (i) = -3/4.

From P(-1,-2), draw PN perpendicular to the given line. (see attachment)

As we know,, m2 = -1/m1

So, the slope of the line PN = 4/3

the equation of the line through P(-1,-2) and having a slope 4/3 is :-

= > y - (-2) = 4/3 * (x - (-1))

= > 3y + 6 = 4x + 4

= > 4x - 3y - 2 = 0....(ii)

which is the required equation of the perpendicular from P to the given line. To find the coordinates of N (the foot of perpendicular), solve (i) and (ii) simultaneously. Multiplying (i) by 3 and

(ii) by 4, and on adding, we get

= > 25x - 44 = 0

= > x = 44/25

Multiplying (i) by 4 and (ii) by 3, and on subtracting, we get :-

= > 25y - 42 = 0

= > y = 42/25

Hence, the coordinates of the foot of the perpendicular are (44/25 , 42/25)

Hope it helps you!!

Find the equation of the perpendicular from the point P(-1,-2) on the line 3x + 4y-example-1
User Ynh
by
2.7k points
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