Respuesta :

Answer:

The first term of the sequence is:

  • a₁ = -3
  • a₂ = 12
  • a₃ = -27
  • a₄ = 48

Step-by-step explanation:

Given the sequence

aₙ = (-1)ⁿ · 3n²

substituting n = 1 to determine the first term

a₁ = (-1)¹ · 3(1)²

a₁ = (-1)¹ · 3(1)²

Applying the exponent rule: [tex]a^1=a[/tex]

a₁ = -1 · 3(1)

a₁ = -1 · 3

a₁ = -3

substituting n = 2 to determine the 2nd term

a₂ = (-1)² · 3(2)²

a₂ = 1 · 3(4)

a₂ = 12

substituting n = 3 to determine the 3rd term

a₃ = (-1)³ · 3(3)²

a₃ = -1 · 3(9)

a₃ = -1 · 27

a₃ = -27

substituting n = 4 to determine the 4th term

a₄ =  (-1)⁴ · 3(4)²

a₄ = 1 · 3(16)

a₄ = 1 · 48

a₄ = 48

Therefore, the first term of the sequence is:

  • a₁ = -3
  • a₂ = 12
  • a₃ = -27
  • a₄ = 48