Question

a2+1/a2=18 find the value of a a+1/a and a-1/a​

Answer 1

In the above Question , the following information is given -

a² + 1 / a² = 18

To find -

[ A ] a + 1 / a

[ B ] a - 1 / a

Solution -

[ A ]

a² + 1 / a² = 18

=> a² + 1 / a² - 2 = 18 - 2

= > a² + 1 / a² - 2 = 16

=> ( a - 1 / a ) ² = 4²

=> ( a - 1 / a ) = 4

[ B ]

a² + 1 / a² = 18

=> a² + 1 / a² + 2 = 18 + 2

=> a² + 1 / a² + 2 = 20

=> ( a + 1 / a ) ² = 20

=> ( a + 1 / a ) = √ { 20 }

=> ( a + 1 / a ) = √ { 4 × 5 }

=> ( a + 1 / a ) = √ { 2² × 5 }

=> ( a + 1 / a ) = 2 √ 5

________________

Answer -

Hence the required answer Becomes -

[ A ] ( a - 1 / a ) = 4

[ B ] ( a + 1 / a ) = 2 √ 5

________$

Answer 2

Step-by-step explanation:

HI DEAR,

a²+1/a² =18

(a+1/a)²= a²+1/a²+2

a+1/a = √20 = 2√5

(a²+1)/a= 2√5

a²+1-2√5a=0

a = √5±2

HOPE IT HELPS...