Question

y+1/y=5 find y^2+1/y^2​.​

Answer 1

Answer:

23

Step-by-step explanation:

Given----> y + 1 / y = 5

To find---> Value of y² + ( 1 / y² )

Solution---> We know that,

y + 1 / y = 5

Squaring both sides we get ,

=> ( y + 1 / y )² = 5²

We know that ,

( a + b )² = a² + b² + 2 ab , applying it here we get,

=> y² + ( 1 / y )² + 2 ( y ) ( 1 / y ) = 25

=> y² + 1 / y² + 2 = 25

=> y² + 1 / y² = 25 - 2

=> y² + 1 / y² = 23

Additional information---->

1) ( a - b )² = a² + b² - 2ab

2) ( a² - b² ) = ( a + b ) ( a - b )

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

4) ( a³ - b³ ) = ( a - b ) ( a² + b² + ab )