Hi MHF, I need some help with 2 problems that I have been stuck with please

1) If and

0 <= theta <= pi/4 , find the value of .

2) In triangle ABC,the angle B is twice the size as compared to that of angle A.

Show that

a)

b) the area of triangle ABC =

(a is the side opposite angle A and b....angle B .....)

For question 1 , I could not draw in terms of a triangle in the quadrant and hence I tried to manipulate it and got to (cheated a little by changing radians to degrees here) and got stuck. I am totally lost on this from here on and my approach is wrong too i guess,since we need to find the value of .

For question 2, i tried to use the law of cosines (to find length of side) to see if i could derive anything but i am stuck with

Any help would be greatly appreciated.