Let the area of the triangle formed by a straight line L : x + by + c = 0 with co-ordinate axes be 48 square units. If the perpendicular drawn from the origin to the line L makes an angle of 45 with the positive x-axis, then the value of b2 + c2 is :
- 90
- 83
- 93
- 97
Answer
(4) 97
Solution
Normal form of the line: x 45 + y 45 = p
x + y = 2p
Comparing with x + by + c = 0: b = 1, c = - 2p
L: x + y + c = 0 meets the axes at (-c, 0) and (0, -c)
Area = 12|c| |c| = 48 c2 = 96
b2 + c2 = 1 + 96 = 97
Answer: (4)