I found a Indices/Algebra question which I think the writer has answered incorrectly. It goes like this;
On the step from last, they get a value of -2 and a positive + t ^ -2. I don't see where this has come from. When I went through this myself, I got a final answer of;
t^2 - (1 / (t^2)) + 2
who is correct?
if you want to do it the long way, this is how
.........hopefully you see how i got to this line. i just expanded the brackets.
Now recall, when multiplying numbers of the same base, we add the indices. that is,
so we have
( becomes since )
Thanks for that, I think I've got it. I think I became phased by the presence of the minus signs in the following calculations;
It feels as if the negativity / positivity of the terms is treated 'crudely' (apologies for the poor description.) For example, in the first, the minus sign of the second term is nudged out of the way in order to make the calculation;