Question

Jika diketahui a = 3 + akar 6 dan b=3 - akar 6 maka a pangkat 2 +b pangkat 2 - 6 ab =

Answer 1

Ingat rumus : a² + b²= ( a + b)² - 2ab
a² + b² - 6ab
=( a+ b)² - 2ab - 6ab
= (a + b)² - 8ab
= ( 3 + √6 + 3 - √6)² - 8(3 + √6)(3 -√6)
= (6)² - 8(9 - 3√6 + 3√6 - 6)
= 36 - 8(3)
= 36 - 24
=12

Answer 2

Diketahui a =3 + √6 dan b = 3 - √6
=> a² + b² - 6ab
=> (3 + √6)² + (3 - √6)² - 6(3 + √6)(3 - √6)
=> (9 + 6 + 6√6) + (9 + 6 - 6√6) - 6(9 - 6)
=> 15 + 15 - 18
=> 12