Question

15.If a = 3 + V8. then find the value of
a-1/a.​

Answer 1

Answer:

Step-by-step explanation:

hiii!!!

here's ur answer...

given a = 3 + √8

therefore 1/a = 1/(3+√8)

= 1/(3+√8) × (3-√8)/(3-√8)

= (3-√8)/(3+√8)(3-√8)

= (3-√8)/(3)²-(√8)²

= (3-√8)/9-8

= 3 - √8

so (a+1/a)² = (3+√8 + 3-√8)²

= (6)²

= 36

Hope this helps you

Plus mark as brainlist

Answer 2

hiii!!!

here's ur answer...

given a = 3 + √8

therefore 1/a = 1/(3+√8)

= 1/(3+√8) × (3-√8)/(3-√8)

= (3-√8)/(3+√8)(3-√8)

= (3-√8)/(3)²-(√8)²

= (3-√8)/9-8

= 3 - √8

so (a+1/a)² = (3+√8 + 3-√8)²

= (6)²

= 36

Hope this helps..!!