Question

If y= 2+root 3 then find the value of y2+1/y2

Answer 1

Step-by-step explanation:

y = 2 +√3

y² + 1/y² = ?

(a + b)² = a² + b² + 2ab

=> a² + b² = (a + b)² - 2ab

Using this formula in the given case, we get

y² + 1/y² = (y + 1/y)² - 2 × y × 1/y

=> y² + 1/y²

= (y + 1/y)² - 2

The calculation below this is done in the picture.

And the final answer is 14.