(1 + x)n ≥ 1 + nx
I can work it down to this step but I have no idea where to go from here to finish the equation.
(1 + x)^k (1 + x) ≥ 1 + x + kx + kx2
I can work it down to this step but I have no idea where to go from here to finish the equation.
(1 + x)^k (1 + x) ≥ 1 + x + kx + kx2
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Looking at the inductive step (you're very close):
(1 + x)^(k+1)
= (1 + x)^k (1 + x)
≥ (1 + kx) (1 + x), by inductive hypothesis
= 1 + (k+1) x + x^2
≥ 1 + (k+1) x + 0
= 1 + (k+1) x.
I hope this helps!
(1 + x)^(k+1)
= (1 + x)^k (1 + x)
≥ (1 + kx) (1 + x), by inductive hypothesis
= 1 + (k+1) x + x^2
≥ 1 + (k+1) x + 0
= 1 + (k+1) x.
I hope this helps!