tana
cotA
Value of
+
1-cotA 1-tanA
Options
O 1 + cosec A sec A
O 1
0sinA/1-COSA
Options 2
Answers
Answer:
To Prove:
(1−cotA)
tanA
+
(1−tanA)
cotA
=secA⋅cosecA+1
Proof:
LHS
⇒
(1−cotA)
tanA
+
(1−tanA)
cotA
Putiing cotA=
tanA
1
⇒
(1−
tanA
1
)
tanA
+
(1−tanA)
tanA
1
⇒
(tanA−1)
tan
2
A
+
(1−tanA)
tanA
1
⇒
tanA−1
tan
2
A−
tanA
1
⇒
tanA(tanA−1)
tan
3
A−1
⇒
tanA(tanA−1)
(tanA−1)
3
+3tanA(tanA−1)
From (a−b)
3
=a
3
−b
3
−3ab(a−b)→a
3
−b
3
=(a−b)
3
+3ab(a−b)
Now,
tanA
(tanA−1)
2
+3tanA
tanA
tan
2
A+1−2tanA+3tanA
tanA
tan
2
A+1
+
tanA
tanA
sinAsecA
sec
2
A
+1
secA⋅cosecA+1=RHS
Step-by-step explanation:
Proof:
LHS
⇒
(1−cotA)
tanA
+
(1−tanA)
cotA
Putiing cotA=
tanA
1
⇒
(1−
tanA
1
)
tanA
+
(1−tanA)
tanA
1
⇒
(tanA−1)
tan
2
A
+
(1−tanA)
tanA
1
⇒
tanA−1
tan
2
A−
tanA
1
⇒
tanA(tanA−1)
tan
3
A−1
⇒
tanA(tanA−1)
(tanA−1)
3
+3tanA(tanA−1)
From (a−b)
3
=a
3
−b
3
−3ab(a−b)→a
3
−b
3
=(a−b)
3
+3ab(a−b)
Now,
tanA
(tanA−1)
2
+3tanA
tanA
tan
2
A+1−2tanA+3tanA
tanA
tan
2
A+1
+
tanA
tanA
sinAsecA
sec
2
A
+1