The equation of the straight line passing through the point (3, 2) and perpendicular to the line y = x is
A. x – y = 5
B. x + y = 5
C. x + y = 1
D. x – y = 1
B. x + y = 5
Explanation:
Given that straight line passing through the point (3, 2)
And perpendicular to the line y = x
Let the equation of line ‘L’ is
y – y1 = m(x – x1)
Since, L is passing through the point (3, 2)
∴ y – 2 = m(x – 3) … (i)
Now, given eq. is y = x
Since, the above equation is in y = mx + b form
So, the slope of this equation is 1
It is also given that line L and y = x are perpendicular to each other.
We know that, when two lines are perpendicular, then
m1 × m2 = -1
∴ m × 1 = -1
⇒ m = -1
Putting the value of m in equation (i), we get
y – 2 = (-1) (x – 3)
⇒ y – 2 = -x + 3
⇒ x + y = 3 + 2
⇒ x + y = 5
Hence, the correct option is (b)