Sece (d) 1-sina
(d)
Prove the following:
tano
(a)
= 1
cose coto
cosece cote
(b)
=
sino tane
sec0 - 1
(c)
sinée
sec?0
1
1
+
= 2sec a
1
1 + sina
1 + sine cose
(e)
+
2seco
1 + sino
cose
1
1
f) 1 + cose
+
1 - coso
= 2 cosec²0
1
g) sece – tane
= seco + tano
1
= coseco + coto
coseco - cote
sind + cose
seco + coseco
sino. cose
tano + tana
)
cote + cota
tana . tano
h)
i)
Ivedanta

Best answer that i found on yahoo ok   set :   x= length of 2nd piece in cm  x- 3= length of 1st piece in cm  x-4= length of 3rd piece in cm  then since you know they all came from the 20 cm ribbon you add them together and set them equal to 20x+ x-3 +x-4 = 20  3x - 7= 20  3x= 27  x= 9  the shortest piece is the third piece which is x- 4  x-4  9-4 = 5  the length of the smallest piece is 5 cm.  the other lengths are  9 cm  6 cm