Question

Under root 1- cosA/1+ cosA= sinA/ 1+ cosA

Answer 1

please see

$sin(a) = 2sin(a \div 2)cos(a \div 2)$

Answer 2

Solution:

LHS = [(√1-cosA)/(√1+cosA)

Multiply numerator and denominator by

[(√1+cosA)/(√1+cosA) we get

= [√(1-cosA)(1+cosA)]/(√1+cosA)²

= √(1-cos²A)/(1+cosA)

= (√sinA)²/(1+cosA)

= sinA/(1+cosA)

=RHS

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