trig Prove each identity ... 1) to 10)

1)cot(x)/csc(x)=cos(x) 2)(sec(x)-1)(sec(x)+1)=tan^2(x) 3)sec(x)-cos(x)=tan(x)sin(x) 4)cos(x)/(1-sin(x))=(1+sin(x))/cos(x)