Prove that, tan-1x+cot-1x=π2,x∈R
Proof:
Let us consider that,
tanA=x⇒cotπ2-A=x∵tanA=cotπ2-A⇒π2-A=cot-1x⇒cot-1x+A=π2⇒cot-1x+tan-1x=π2∵A=tan-1x∴cot-1x+tan-1x=π2,x∈R
Hence, proved.
Prove that limx→a+[x] =[a] for all a∈R. Also, prove that limx→1−[x]=0
Prove that:
n! / r! x (n-r)! + n! / (r-1)! x (n-r+1) = (n+1)! / r! x (n-r+1)!
If the coefficients of xr−1,xr and xr+1 in the binomial expansion of (1+x)n are in AP, prove that n2−n(4r+1)+4r2−2=0
If both (x - 2) and (x−12) are factors of px2+5x+r, prove that p = r.