Use the explicit formula to find the first four terms of the sequence

Question

 a_n =(-1)^n-1(-n-1)

enter the terms separated by a comma

Answer 1

a₁ = (-1)^1-1(-1-1) = (-1)⁰(-2) = -2

 

a₂ = (-1)^2-1(-2-1) = (-1)¹(-3) =  3

 

a₃ = (-1)^3-1(-3-1) = (-1)²(-4) = -4

 

a₄ = (-1)^4-1(-4-1) = (-1)³(-5) =  5