please explain
if (7+√5)/(7-√5) - (7-√5)/(7+√5) = a+(7/11)√5b find value of a and b
Answers
Answered by
335
Well, first you need to simplify your expression.
How ?
Simple! By rationalising.
(7+√5)/(7-√5) - (7-√5)/7+√5)
Rationalise both the terms
(7+√5)² - (7-√5)²/ 49 - 5
= 49 + 14√5 + 5 - 49 + 14√5 - 5/ 44
= 28√5/44
= 7√5/11
Now, 7√5/11 = a + (7/11) √5b
On comparison,
a = 0
b = 1
How ?
Simple! By rationalising.
(7+√5)/(7-√5) - (7-√5)/7+√5)
Rationalise both the terms
(7+√5)² - (7-√5)²/ 49 - 5
= 49 + 14√5 + 5 - 49 + 14√5 - 5/ 44
= 28√5/44
= 7√5/11
Now, 7√5/11 = a + (7/11) √5b
On comparison,
a = 0
b = 1
rishab260:
I was also doing same thing but I wasn't sure about my answer . thanks
Pleasure is all mine :)
Answered by
8
Step-by-step explanation:
Well, first you need to simplify your expression
How ? simple by nationalising
7+√5)/(7-√5) - (7-√5)/(7+√5)
Rationalise both the terms
(7+√5²)/(7-√5²) 49 -5.
Similar questions