Question

cot
À/2 =
sin A/1 - cos A

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Answer 1

Derivation

Formulae used:

1. sin 2A = 2•sinA•cosA
2. 1-cos2A = 2•sin²A

LHS:

cot (A/2) = cos (A/2) /sin (A/2)

= ( cos (A/2) /sin (A/2) ) × ( 2 sin (A/2) / 2sin (A/2) )

-------( multiply and divide with 2sin(A/2) on both numerator and denominator )-------

= ( 2sin(A/2)•cos(A/2) ) / ( 2sin(A/2)•sin(A/2) )

= sin 2(A/2) / (1 - cos 2(A/2)

= sin A / (1-cos A)

• LHS = RHS

.° . Hence Proved.

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Answer 2

Answer:

please give the answer