Question
Question: Roots of the equation ax<sup>2</sup> + bx + c = 0 are sin a and cos a then...
Roots of the equation ax2 + bx + c = 0 are sin a and cos a then
A
(a – c)2 = b2 + c2
B
(a + c)2 = b2 – c2
C
a2 = b2 –2ac
D
a2 + b2 = 2ac
Answer
a2 = b2 –2ac
Explanation
Solution
sin a + cos a = –ab, sin a cos a = ac eliminate 'a'