1.

If x = \(\frac{1}{4-\sqrt{15}}\) , y = \(\frac{1}{4+\sqrt{15}}\) , then value of x3 + y3 is1. 486 2. 439 3. 488 4. 476

Answer»

3. 488

x = 4 + √15

y = 4 - √15

x + y = 8

xy = 1

x3 + y3 = (x + y) ((x + y)2 - 3xy)

= 8 (64 - 3)

= 8 (61)

= 488



Discussion

No Comment Found

Related InterviewSolutions