Find the equation of straight line passing through (2, 3) and perpendicular to the line 3x+2y+4=0
A.
3y = 5x - 2
B.
y = 5/3× − 2
C.
None of these
D.
3y = 2x + 5
Correct Answer: 3y = 2x + 5
Explanation
3x + 2y + 4 = 0
Rearrange:
2y = −3x − 4
Divide both sides by 2
y = (−3× − 4)/2
y = −3/2×−2
∴ the gradient of the line 3x + 2y + 4 = 0 is −3/2
If two lines are perpendicular to each other ∴ m1xm2 = -1
Let m1 =−3/2 ∴ m2 = −1/m1 = −1/(−3/2) = 2/3
From the equation of a line which is given as m = (y − y1)/x − x1) where (x1, y1) = (2, 3)
∴ 2/3 = (y − 3)/x − 2)
=3(y - 3) = 2(x - 2)
= 3y - 9 = 2 x -4
= 3y = 2 x -4 + 9
∴ 3y = 2x + 5
3x + 2y + 4 = 0
Rearrange:
2y = −3x − 4
Divide both sides by 2
y = (−3× − 4)/2
y = −3/2×−2
∴ the gradient of the line 3x + 2y + 4 = 0 is −3/2
If two lines are perpendicular to each other ∴ m1xm2 = -1
Let m1 =−3/2 ∴ m2 = −1/m1 = −1/(−3/2) = 2/3
From the equation of a line which is given as m = (y − y1)/x − x1) where (x1, y1) = (2, 3)
∴ 2/3 = (y − 3)/x − 2)
=3(y - 3) = 2(x - 2)
= 3y - 9 = 2 x -4
= 3y = 2 x -4 + 9
∴ 3y = 2x + 5