![If a = 5 + 2√6 and b = 1/a, then what will be the value of a^2+b^2 ? - Part 2](https://d1avenlh0i1xmr.cloudfront.net/8aaebc8d-b5ec-4614-ac18-9fed1072c672/slide29.jpg)
![If a = 5 + 2√6 and b = 1/a, then what will be the value of a^2+b^2 ? - Part 3](https://d1avenlh0i1xmr.cloudfront.net/1a32ff11-8478-442a-a643-e35f405e274c/slide30.jpg)
Rationalising
Rationalising
Last updated at April 16, 2024 by Teachoo
If a = 5 + 2√6 and b = 1/𝑎, then what will be the value of 𝑎^2+𝑏^2 ? a = 5 + 2√6 b = 1/𝑎 = 1/(5 + 2√6) = 1/(5 + 2√6) × (5 − 2√6)/(5 − 2√6) = (5 − 2√6)/(5^2 − (2√6)^2 ) = (5 − 2√6)/(25 − 24) We know that 〖(𝑎+𝑏)〗^2 = 𝑎^2+𝑏^2+ 2𝑎𝑏 𝒂^𝟐+𝒃^𝟐 = 〖(𝒂+𝒃)〗^𝟐 − 𝟐𝒂𝒃 Here, 𝒂+𝒃 = (5+2√6)+5(5−2√6) 𝒂𝒃 = (5+2√6) (5−2√6) Thus, 𝑎^2+𝑏^2 = 〖(𝑎+𝑏)〗^2 − 2𝑎𝑏 𝑎^2+𝑏^2=〖10〗^2−2 × 1 =100−2 =𝟗𝟖