Question

qual o resultado de Bhaskara sendo ∆= 72 a) 2. b) -4. c) -7

Answer 1

∆=-b²-4.a.c
∆=-(-4)²-4.2.(-7)
∆=16+56
∆=72

x=-b±√∆/2a
x=-(-4)±√72/2.2
x=4±8,4/4
x¹=4+8,4/4 => 12,4/4 => 3,1
x²=4-8,4/4 => -4,4/4 => -1,1

Answer 2

Δ = b² - 4.a.c
Δ = (-4)² - 4.2.-7
Δ = 16 + 56
Δ = 72 ⇒ √ 72 = √2².2.3²
Δ = 2.3 √2 ⇒6√2
x´= - b + ou - 6  √2 / 2 . 2
x´= -(-4) + 6 √2/4
x´= 4 + 6 √2/4
x´= 2 + 3 √2 /2
x ´´ = 4 - 6 √2/4
x ´´ = 2 - 3 √2/2

S ={ 2 - 3 √2  / 2  ;  2 + 3√2 / 2}