The given sequence is:
-1, 1, 3, 5, 7, ....
If we observe the sequence, each term is 2 more than the previous term. Since the difference among the terms is common, the sequence is an AP.
The general term of the sequence will be:
[tex]a_{n}= a_{1}+(n-1)d \\ \\
a_{1}= -1 \\ \\
d=2 \\ \\
a_{n}=-1 +(n-1)*2=-1+2n-2=2n-3[/tex]
So, the 11th term of the sequence will be:
[tex] a_{11}=2(11)-3=19 [/tex]
