Question

`(sqrt(7)-sqrt(5))/(sqrt(7)+sqrt(5))+(sqrt(7)+sqrt(5))/(sqrt(7)-sqrt(5))` के बराबर है।
A. 12
B. `6sqrt(35)`
C. `6`
D. `2sqrt(35)`

Answer 1

Correct Answer - A
`(sqrt(7)-sqrt(5))/(sqrt(7)+sqrt(5))+(sqrt(7)+sqrt(5))/(sqrt(7)-sqrt(5))`
`implies((sqrt(7)-sqrt(5)))/((sqrt(7)+sqrt(5)))xx((sqrt(7)-sqrt(5)))/((sqrt(7)-sqrt(5)))`
`+(sqrt(7)+sqrt(5)(sqrt(7)+sqrt(5)))/((sqrt(7)-sqrt(5))(sqrt(7)+sqrt(5)))`
`implies ((sqrt(7)-sqrt(5))^(2))/2+((sqrt(7)+sqrt(5))^(2))/2`
`implies(7+5-2sqrt(35)+7+5+2sqrt(35))/2`
`implies24/2=12`