A line through A(-2,6) and B(4,b) is perpendicular to the line 2x - 4y = 5. The value of b is
Slope of the line AB = b−64+2
= b−66
Slope of line 2x−4y=5 is
−4y=−2x+5
y=12x−54 [ slope is 12]
Since the lines are perpendicular
b−66 × 12 = -1
⇒ b−6=−12 or b=−6