Let t = |ax1+by1+c√a2+b2|. Find the lenght of perpendicular from p(x1,y1) on ax+by+c=0 in terms of t.
A
t
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is A
t
Perpendicular distant of p(x1,y1) from ax1+by1+c is given by |ax1+by1+c√a2+b2|. We can derive this formula in the following way.
We want to find d or PR. we can find d if we know the co-ordinates of R. 1. Find the slope of PR assuming R≡(x2,y2) 2. Find the slope of PR as −1m, where m is the slope of L. (PR and L are perpendicular) 3. Equate the slopes in 1 and 2 to get a relation between x2andy2 4. We get one more relation because (x2,y2) lies on L. 5. Use 3 and 4 to find x2,y2 6. Find the distance using distance formula It is good to remember both formula and the method.