Question

 If a = 2√2 - √7 then a + 1/a is *​

Answer 1

Answer:

4√2

given a=2√2-√7

1/a = 1/2√2-√7 = 2√2+7/8-√7 = 2√2+√7

therefore, a+1/a = 2√2-√7+2√2+√7 = 2√2+2√2 = 4√2

Answer 2

Step-by-step explanation:

we have value of a

now put valule of a in a+1/a

i.e. a+1/a

2√2-√7 + 1/ 2√2-√7

now by cross multiplying

(2√2-√7)² +2√2-√7

-----------------------------

2√2-√7

by (a-b)² = a² - 2ab + b²

(2√2)² - 2 × 2√2 × √7 + (√7)²

8 - 4√9 + 49

57 - 4√9

57 - 4 × 3√3

57 - 12 √3

45√3