Let P(n) be true for n=m
Also when n=1,(1+x)1=1+,x. so in this case, inequality does not hold.
But when n=2
∴(1+x)2=1+2x+x2>1+2x
Thus P(n) is true for n=2
(1+m)m>1+mx ....(1)
Since x>−1, multiplying by x+1,
P(m+1)=(1+x)m+1=(1+x)m(1+x)>(1+mx)(1+x),by(1)
=1+(m+1)x+mx2
=1+(m+1)x+mx2>1+(m+1)x∵mx2>0
Above relation shows that P(n) is true for n=m+1
Hence P(n) is true universally if n≥2