Question

plse give my correct answer ,tap and see the question
​

Answer 1

Given:-

• a + 1/a = 11

To find:-

• a² + 1/a² = ?

Answer:-

Given that,

a + 1/a = 11

On squaring both sides, we get,

→ (a + 1/a)² = 11²

Now, we will use the formula

(x + y)² = x² + y² + 2xy, here x = a, and y = 1/a

→ a² + 1/a² + (2 * a * 1/a) = 121

→ a² + 1/a² + 2 = 121

→ a² + 1/a² = 121 - 2

→ a² + 1/a² = 119 Ans

Extra knowledge:-

• (a - b)² = a² + b² - 2ab
• a² - b² = (a + b)(a - b)
• (a + b)³ = a³ + b³ + 3ab(a + b)
• (a - b)³ = a³ - b³ - 3ab(a - b)
• a³ + b³ = (a + b)(a² + b² - ab)
• a³ - b³ = (a - b)(a² + b² + ab)
• (a + b + c)² = a² + b² + c² + 2(ab + bc + ca)
• a³ + b³ + c³ - 3abc = (a + b + c)(a² + b² + c² - ab - bc - ca)