(sinx-cosx)(sinx+cosx)

i dont know man i just got the stuff today and i fell asleep throughout the whole lecture even though its a 6 day course :\

but how do i do it?
1.(sinx-cosx)(sinx+cosx)
2.(1+tanx)^2
3.(1-sinx)(1+sinx)

i know how to factor it but i dont get the part where you have like "tan^2x+cosx" dont you have to use like sin=1/csc...............................… help thanks in advance

Not sure exactly what you wanted to do with these so I just reduced them.

1) (sin(x)-cos(x))(sin(x)+cos(x))
expanding
sin^2(x) + sin(x)*cos(x) - sin(x)*cos(x) - cos^2(x)
reducing
sin^2(x) - cos^2(x)

2) (1+ tan(x))^2
expanding
(1+tan(x)) * (1+ tan(x))
1 + tan(x) + tan(x) + tan^2(x)
reducing
1 + 2*tan(x) + tan^2(x)
substituting since sec^2(x) = 1+tan^2(x)
2*tan(x) + sec^2(x)

3) (1-sin(x)) * (1+sin(x))
expanding
1 - sin(x) + sin(x) - sin^2(x)
reducing
1 - sin^2(x)
substituting since sin^2(x) + cos^2(x) = 1
cos^2(x)