Find the equation of the lines through the point (3, 2) which make an angle of 45o with the line x – 2y = 3.


Let the slope of the required line be m1.


The given line can be written as , which is of the from y = mx + c


Thus, Slope of the given line = m2 =


It is given that the angle between the required line and line x – 2y = 3 is 45o.


We know that if Ɵ is the acute angle between lines l1 and l2 with slopes m1 and m2 respectively, then








and


2 + m1 = 1- 2m1 or 2 + m1 = -1 + 2m1


m1 = or m1 = 3


Now, when m1 = 3, then,


The equation of the line passing through (3,2) and having a slope of 3 is:


y – 2 = 3(x – 3)


y -2 = 3x – 9


3x – y = 7


And, when m1 =


The equation of the line passing through (3,2) and having a slope of is:



3y – 6 = -x + 3


x + 3y = 9


Therefore, the equations of the lines are 3x – y = 7 and x + 3y = 9.


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