Question

No 16, jika a + b = 1 dan a^2 + b^2 = 2 maka a^4 + b^4=

Answer 1

.
a²+b² = (a+b)² - 2ab
2 = 1² - 2ab
2ab = 1- 2 = -1
ab = - 1/2
.
a⁴ + b⁴ = (a² +b²)² - 2(ab)²
a⁴ + b⁴ = (2)²- 2(-1/2)²
a⁴ + b⁴ = 4 - 2(1/4) = 4 - 1/2
a⁴ + b⁴ = 3 1/2