9. Prove that, (1 - Cos? A) cosec? A= 1.
Answers
Explanation:
We need to prove
1+cosA
1−cosA
=cosecA−cotA
By taking L.H.S. =
1+cosA
1−cosA
=
1+cosA
1−cosA
×
1−cosA
1−cosA
=
1−cos
2
A
(1−cosA)
2
=
sin
2
A
(1−cosA)
2
=
sinA
1−cosA
=
sinA
1
−
sinA
cosA
=cosecA−cotA= R.H.S.
Hence, proved
Answer:
We need to prove
1+cosA
1−cosA
=cosecA−cotA
By taking L.H.S. =
1+cosA
1−cosA
=
1+cosA
1−cosA
×
1−cosA
1−cosA
=
1−cos
2
A
(1−cosA)
2
=
sin
2
A
(1−cosA)
2
=
sinA
1−cosA
=
sinA
1
−
sinA
cosA
=cosecA−cotA= R.H.S.
Hence, proved