Q29 of 59 Page 178

The equations of the lines which pass through the point (3, –2) and are inclined at 60° to the line is

Given equation is √3x + y = 1

and θ = 60°


Firstly, we find the slope of the given equation


√3x + y = 1


y = 1 - √3x


or y = (-√3)x + 1


Since, the above equation is in y = mx + b form.


So, the slope of this equation m1 = -√3


Let m2 be the slope of the required line.


Now, we find the value of m2, by using the formula



Putting the values of m1 and m2 in above eq., we get



[ tan 60° = √3]



Taking (+) sign, we get



-√3 – m2 = √3(1 - √3m2)


-√3 – m2 = √3 - 3m2


3m2 – m2 = √3 + √3


2m2 = 2√3


m2 = √3


Taking (-) sign, we get



√3 + m2 = √3(1 - √3m2)


√3 + m2 = √3 - 3m2


3m2 + m2 = 0


4m2 = 0


m2 = 0


, Equation of line passing through (3, -2) with slope √3 is


y – y1 = m(x – x1)



y + 2 = √3x – 3√3


√3x – y – 3√3 – 2 = 0


√3x – y – (3√3 + 2) = 0


and Equation of line passing through (3, -2) with slope 0 is


y – y1 = m(x – x1)


y (-2) = 0 (x – 3)


y + 2 = 0


Hence, the required equations are √3x – y – (3√3 + 2) = 0 and y + 2 = 0


Hence, the correct option is (a)

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