You can put this solution on YOUR website! Answer part 1: . Add me on Skype I'll send you the other 2 parts. This is an app called Symbolab that can do almost anything in math. My skype is DAWNPLAYA55. Don't be surprised tha I'm so young :)
You can put this solution on YOUR website! term on left over (1-sinx^2)
{cos x(1-sinx) +cos x(1+sinx)}/1-sinx^2
cos x-cosx sinx + cosx+ cosx sinx=2cosx
1-sinx^2=cosx^2
(2cosx)/(cosx^2) =2/cos x
term on right: tanx^2+ 1=secx^2. {sinx^2/cosx^2} +1 ={sinx^2+cosx^2/cosx^2} = 1/cosx^2=secx^2.
secx^2/sec x=sec x = 1/cos x
2* (1/cosx)= 2/cosx