Solveeit Logo

Question

Question: If sin a and cosa are roots of the equation px + qx + r = 0, then....

If sin a and cosa are roots of the equation px + qx + r = 0, then.

A

p2 – q2 + 2pr = 0

B

(p + r)2 = q2 – r2

C

p2 + q2 – 2pr = 0

D

(p – r)2 = q2 + r2

Answer

p2 – q2 + 2pr = 0

Explanation

Solution

Here sin a + cos a = –q/p, sin a cos a = r/p

(sin a + cos a)2 = q2/p2

Ž sin2a + cos2a + 2 sin a cos a + q2/p2

Ž 1 + 2r/p = q2/p2 Ž p2 – q2 + 2pr = 0