Please check if i have done these correctly.
Can i also write f''(x) as ??
Your is incorrect as it should be since we started with a factor of and multiplied it by again when we use the chain rule to get . And as for your re-writing of , you just moved the term around...that's not different in any meaningful way ie. just like and are obviously the same since multiplication in is commutative. If you wish to factor you can rewrite it as