If a = 5 + 2√6 and b = 1/a, then what will be the value of a^2+b^2 ?

If a = 5 + 2√6 and b = 1/a, then what will be the value of a^2+b^2 ? - Part 2
If a = 5 + 2√6 and b = 1/a, then what will be the value of a^2+b^2 ? - Part 3

Go Ad-free

Transcript

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

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo