The unit step response of a system with the transfer function

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The unit step response of a system with the transfer function
G(s) = 1 - 2s
1 + s

is given by which one of the following waveforms?

Correct Option: A

Y(s) = G(s) × U(s)

∴ Y(s) =	1 - 2s	.	1
	(1 + s)		s

Now using partial fraction concept

∴ Y(s) =	A	+	B
	(s)		(s + 1)

A = 1, B = -3
∴ y(t) = u(t) – 3e^–t u(t)
∴ y(t) = (1 – 3e – t) u(t)