we got a bunch of review problems for the test thats coming up in a few days, I got most of them figured out but am stuck on these 3 if anyone could give me a few pointers of where to head

1.Solved2.Code:

TANx + TAN^3x + SINx

---------------------- = COSx + SEC^2x

TANx

TANx(1 + TAN^2x) + SINx

-------------------------- =

TANx

TANx(SEC^2x) + SINx

--------------------- =

TANx

(SEC^2x) + SINx =

Solved3.Code:

COS(x+y)

--------- = 1 - TANxTANy

COSxCOSy

COSxCOSy - SINxSINy

--------------------- =

COSxCOSy

COSxCOSy - TANxTANy =

not sure how to turn COSxCOSy into 1

if anyone could give me suggestions of where to go for the next steps in these, that would help me out alot, I'll post back if I figure anything out in the mean timeCode:`SIN3x COS3x`

------ - ------ = 2

SINx COSx

SIN(x+2x) COS(x+2x)

--------- - ---------- =

SINx COSx

SINxCOS2x + COSxSIN2x COSxCOS2x - SINxSIN2x

----------------------- - ----------------------- =

SINx COSx

COSxSINxCOS2x + COS^2xSIN^2x - SINxCOSxCOS2x - SIN^2xSIN^2x

--------------------------------------------------------------- =

SINxCOSx

COS^2xSIN2x -SIN^2xSIN2x

---------------------------- =

SINxCOSx

COS^2x(2SINxCOSx) - SIN^2x(2SINxCOSx)

------------------------------------ =

SINxCOSx

2SINxCOSx(COS^2x - SIN^2x)

----------------------------- =

SINxCOSx

2(COS^2x - SIN^2x) =