Answer:
cscu – cotu = sinu/1 + cosu
1/sinu – cosu/sinu= sinu/1 + cosu
1 – cosu/sinu= (sinu)(1 – cosu) ÷ (1 + cosu)(1 – cosu)
1 – cosu/sinu= 1 – cosu/sinu
Hence Proved!!
-TheUnknownScientist 72
