Can anyone please explain these problems to me?? I really need help!I need to simplify these trig expressions but I don't understand how my teacher is doing it at all and I have a quiz on this tomorrow! I've really been trying but I just don't get it!

1)Mulitply:
[cosx/(1-cosx)][1+sinx/(1+sinx)]

2)Rewrite over common denominator:
[1/(1-cosx)]+[1/(1+cosx)]

3)Establish the identity:
[(1-cot^2x)/(1+cot^2x)]+1=2sin^2x

1 answer

cos/(1-cos) * ((1+sin)+sin)/(1+sin)

cos(1+2sin)/((1-cos)(1+sin))
Not sure how to make it any simpler. No chance of a typo in the problem?

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((1+cos) + (1-cos))/(1-cos)(1+cos)

2/sin^2

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(1-cos^2/sin^2)/(1+cos^2/sin^2) + 1

(sin^2 - cos^2)/sin^2) / ((sin^2+cos^2)/sin^2) + 1

(sin^2-cos^2)/(sin^2+cos^2) + 1

(sin^2 - cos^2) + 1
sin^2 + 1-cos^2
sin^2+sin^2
2sin^2