Find the equation of the line whose perpendicular distance from the origin is 4 units and the angle which the normal makes with the positive direction of x–axis is 15°.
Given: p = 4, α = 15°
Concept Used:
Equation of line in normal form.
Explanation:
We know that, cos 15° = cos (45° – 30°) = cos45°cos30° + sin45°sin30°
cos(A – B) = cosAcosB + sinAsinB
And sin 15 = sin (45° – 30°) = sin 45° cos 30° – cos 45° sin 30°
sin (A – B) = sinAcosB – cosAsinB
So, the equation of the line in normal form is
Formula Used: x cos α + y sin α = p
⇒ (√3 + 1)x + (√3 – 1)y = 8√2
Hence, the equation of line in normal form is (√3 + 1)x + (√3–1)y = 8√2