Rewrite this as
Now let
giving us
which implies that
So either
or
So backsubbing we get
or
Note this is very useful trick...for example say you were given
solve
Let
do the same thign
or
rewriting this as
let
same trick
Remember that when you solve the u formula with the quadratic formula that you must take the inverse to get the actual answer
for example
in the sin(x) one
lets say after you sub you get
then by backsubbing you get
This is a very useful tool