Question

Polinom kls 11, tlg pake caranya

Answer 1

(x1 + x2 + x3)²

= (x1 + x2 + x3) . (x1 + x2 + x3)

= (x1)² + x1 . x2 + x1 . x3 + x1 . x2 + (x2)² + x2 . x3 + x1 . x3 + x2 . x3 + (x3)²

= (x1)² + (x2)² + (x3)² + 2 . x1 . x2 + 2 . x1 . x3 + 2 . x2 . x3

= (x1)² + (x2)² + (x3)² + 2 . (x1 . x2 + x1 . x3 + x2 . x3)

x^3 - 2x² - x + 2 = 0

a = 1; b = -2; c = -1; d = 2

(x1)² + (x2)² + (x3)²

= (x1 + x2 + x3)² - 2 . (x1 . x2 + x1 . x3 + x2 . x3)

= (-b/a)² - 2 . c/a

= (- (-2)/1)² - 2 . (-1)/1

= 4 + 2

= 6

Answer 2

Matematika

x³ - 2x² - x + 2 = 0

a = 1

b = -2

c = -1

d = 2

x1 + x2 + x3 = - b/a

= - (-2) / 1

= 2

x1.x2 + x1.x3 + x2.x3 = c/a

= -1 / 1

= -1

nilai dari

= x1² + x2² + x3²

= (x1 + x2 + x3)² - 2(x1x2 + x1x3 + x2x3)

= (2)² - 2(-1)

= 4 + 2

= 6