Question
Question: If x<sup>2</sup> + y<sup>2</sup> = t + \(\frac{1}{t}\), x<sup>4</sup> + y<sup>4</sup> = t<sup>2</sup...
If x2 + y2 = t + t1, x4 + y4 = t2 + t21, then –
A
x3 yy1 = –1
B
y2 = 2y/x2
C
x4 yy2 = 2
D
All correct
Answer
All correct
Explanation
Solution
Eliminate t , by
(x2 + y2)2 = t2 + t21 +2 = x4 + y4 + 2
Ž 2x2y2 = 2
Ž x2y2 = 1