Integration sikhao!!!

This thread features my doubts in integration problems.....others can feel free to post their own!!!

OK HERE GOES:

I came across these questions in Brilliant Tutorials Elite Course ......

(I)
Both of the questions below have one or more options correct, but funnily enough i was able to pick out only one correct option in each question....

Pls give all possible correct options for both questions:

1)\int \frac{2x.dx}{1+x^4}

(a) tan^-1(x²)+c (b)1/2 tan^-1(x²)+c

(c)log(1+x⁴)+c (d) tan^-1(1/x²)+c

2)\int \frac{dx}{x+\sqrt{x}}

(a)log(1+√x)+c (b) 1/2 log(1+√x)+c

(c)2log(1+√x)+c (d)-1/2 log(1+√x) +c