Question
Question: If sin q and cos q are the roots of the equation lx<sup>2</sup> + mx + n = 0, then –...
If sin q and cos q are the roots of the equation
lx2 + mx + n = 0, then –
A
l2 – m2 + 2ln = 0
B
l2 + m2 + 2ln = 0
C
l2 – m2 – 2ln = 0
D
l2 + m2 – 2ln = 0
Answer
l2 – m2 + 2ln = 0
Explanation
Solution
sinq + cos q = –m/l ………(1)
sinq . cos q = n/l ………(2)
squaring of (1) Ž 1 + 2(n/l) = l2m2
Ž m2 = 2nl + l2