Urgent a level maths help

I cannot do a single one of these questions! If anyone can even manage one of them that would be fab thank you

They're trig

1st : https://www.thestudentroom.co.uk/showthread.php?p=81200434

2nd: small angle approximations

3rd: 3a) use tan x = sin x / cosx, sec x = 1 / cos x

4 find BC, then find AC

use pythagoras

5 Expand using Rsin(x+alpha) = Rsinx cos alpha + Rcosx sin alpha

6 Expand, sin^2 x + cos^2 x = 1, 2sinxcosx = sin 2x

7 Write it in the form required

b) use (a) to write it down

c) solve an equation

1st : https://www.thestudentroom.co.uk/showthread.php?p=81200434

2nd: small angle approximations

3rd: 3a) use tan x = sin x / cosx, sec x = 1 / cos x

4 find BC, then find AC

use pythagoras

5 Expand using Rsin(x+alpha) = Rsinx cos alpha + Rcosx sin alpha

6 Expand, sin^2 x + cos^2 x = 1, 2sinxcosx = sin 2x

7 Write it in the form required

b) use (a) to write it down

c) solve an equation

for number 2 do i input the double angle formula for tan2theta and theta in the place of sintheta ? what else do i put in? stuck on 2cos3theta