If $y + \dfrac{1}{y} = 2$, then $y^5 + \dfrac{1}{y^5}$ =

1. 5

2. 3

3. 2

4. 1

If $a^2 - \dfrac{1}{a^2} = 7$, then $a^4 + \dfrac{1}{a^4}$ =

1. 49

2. 51

3. 53

4. 60

If $\dfrac{a}{b} + \dfrac{b}{a} = 1$ (a, b ≠ 0), then a³ + b³ =

1. 0

2. 1

3. 2

4. 8

If $p + \dfrac{1}{p} = x\text{ and }p - \dfrac{1}{p} = y$, then the relation between x and y is :

1. x² = y²

2. x² + y² = 4

3. x² - y² = 4

4. xy = 2