Question

Find the square of px +qy

Answer 1

Step-by-step explanation:

p²x²+q²y²+2pqxy OK friend this is urs answer

Answer 2

ANSWER

Let the line px + qy + r = 0        ..(1)

touch the circle x2 + y2 = a2          .(2)

at the point (h, k).

Now the equation of tangent at (h, k) is

xh + yk - a2 = 0            .(3)

Comparing (1) and (3), we get ph=qk=r−a2

whence h = -a2 p/r and k = a2 q/r 

Since (h , k) lies on the given circle ∴ from (2) 

a4 p2/r2 + a4 q2/r2 a2 

or r2 = a2 (p2 + q2)

which is the required condition and the point of

contact is (- a2 p/r , - a2 q/r).