Question

a+a/1=5 find a2+1/a2=??

Answer 1

hope this will help....

Answer 2

Correct Question :-

If a + 1/a = 5, then find the value of a² + 1/a²

Answer :-

a² + 1/a² = 23

Solution :-

a + 1/a = 5

Squaring on both sides

(a + 1/a)² = (5)²

⇒ (a + 1/a)² = 25

[Sine (5)² = 5 * 5 = 25]

We know that

(x + y)² = x² + y² + 2xy

Here x = a, y = 1/a

By substituting the values

⇒ (a)² + (1/a)² + 2(a)(1/a) = 25

⇒ a² + 1²/a² + 2 = 25

Transpose 2 to RHS (2 becomes - 2)

⇒ a² + 1/a² = 25 - 2

⇒ a² + 1/a² = 23

Therefore the value of a² + 1/a² = 23

Identity used :-

• (x + y)² = x² + y² + 2xy