It depends what you want exactly.
Let's say you have two vectors a and b:
a=[1;2;3;4];
b=[0;2;3;5];
To find the indices where a equals to b, you can simply compute:
a == b
ans =
4×1 logical array
0
1
1
0
To get the values and the indices where a equals to b, you can also have a look at the find function.
