COMEDK2018MathematicsStraight Lines
If the line through A=(4,-5) is inelined at an angle 45^ with the positive direction of the X -axis, then the coordinates of the two points on opposite sides of A at a distance of 3 2 units are
Options
- A(7,2),(1,8)
- B(7,2),(1,-8)
- C(7,-2),(1,-8)
- D(7,2),(-1,8)
Correct answer
C. (7,-2),(1,-8)
Step-by-step solution
If the line is inclined at angle 45^ with the positive direction of the X -axis i.e. the points are situated at angle =45^ from X -axis at a distance r=3 2 from point (4,-5) . The two points can be given by (x₀ r , y r ) The points are aligned (4& .+3 2 45^ ,-5+3 2 45^ ) &= (4+3 2 1 2 ,-5+3 2 1 2 )=(7,-2) aligned aligned & and (4-3 2 45^ ,-5-3 2 45^ ) &= (4-3 2 1 2 ,-5-3 2 1 2 )=(1,-8) aligned Thus, the points are (1,-8) and (7,-2) .