If
1+cosA
1−cosA
=x, then the value of x is:
- A(cotA+cscA)
2 - B(cotA−cscA)
2 - CcotA−cscA
- DcotA+cscA
Solution & Step-by-step Explanation
Given expression:
x=
1+cosA
1−cosA
Rationalizing the numerator or the denominator, let's multiply both the numerator and the denominator by (1−cosA):
x=
(1+cosA)(1−cosA)
(1−cosA)(1−cosA)
x=
1−cos
2
A
(1−cosA)
2
Since 1−cos
2
A=sin
2
A:
x=
sin
2
A
(1−cosA)
2
x=(
sinA
1−cosA
)
2
x=(
sinA
1
−
sinA
cosA
)
2
x=(cscA−cotA)
2
Since (a−b)
2
=(b−a)
2
, this can also be written as:
x=(cotA−cscA)
2
x=
1+cosA
1−cosA
Rationalizing the numerator or the denominator, let's multiply both the numerator and the denominator by (1−cosA):
x=
(1+cosA)(1−cosA)
(1−cosA)(1−cosA)
x=
1−cos
2
A
(1−cosA)
2
Since 1−cos
2
A=sin
2
A:
x=
sin
2
A
(1−cosA)
2
x=(
sinA
1−cosA
)
2
x=(
sinA
1
−
sinA
cosA
)
2
x=(cscA−cotA)
2
Since (a−b)
2
=(b−a)
2
, this can also be written as:
x=(cotA−cscA)
2