Question

find y^2+1/y^2 if y-1/y=5​

Answer 1

ANSWER.

• y² + 1/y² = 27.

SOLUTION.

Given –

→ y - 1/y = 5

Squaring both sides, we get,

→ (y - 1/y)² = 5²

→ y² + 1/y² - 2 = 25

Adding 2 to both sides, we get,

→ y² + 1/y² - 2 + 2 = 25 + 2

→ y² + 1/y² = 27

★ So, the value of y² + 1/y² is 27.

LEARN MORE IDENTITIES.

• (a + b)² = a² + 2ab + b²
• (a - b)² = a² - 2ab + b²
• a² - b² = (a + b)(a - b)
• (a + b)³ = a³ + 3ab(a + b) + b³
• (a - b)³ = a³ - 3ab(a - b) - b³
• a³ + b³ = (a + b)(a² - ab + b²)
• a³ - b³ = (a - b)(a² + ab + b²)