( \frac 1 %2B \sin \theta - \cos \theta 1 %2B \sin \theta %2B

1.	( \frac 1 %2B \sin \theta - \cos \theta 1 %2B \sin \theta %2B \cos \theta ) ^ 2 = \frac 1 - \cos \theta 1 %2B \cos \theta
Answer» LHS = [(1+sinA-cosA )/(1+sinA+cosA)]² =[ (1+sin²A+cos²A+2sinA-2sinAcosA-2cosA)/(1+sin²A+cos²A+2sinA+2sinAcosA+2cosA) ]² = [( 1+1+2sinA-2sinAcosA-2cosA)/(1+1+2sinA+2sinAcosA+2cosA)]² = { ( 2(1+sinA) -2cosA(sinA+1) / [ 2(1+sinA) + 2cosA(sinA +1 ) ]}² = { (2(1+sinA)[1 - cosA] /[2(1+sinA )(1 + cosA )] }² = [ ( 1 - cosA ) / ( 1 + cosA ) ]² = RHS

( \frac 1 %2B \sin \theta - \cos \theta 1 %2B \sin \theta %2B \cos \theta ) ^ 2 = \frac 1 - \cos \theta 1 %2B \cos \theta

Answer»

LHS = [(1+sinA-cosA )/(1+sinA+cosA)]²

=[ (1+sin²A+cos²A+2sinA-2sinAcosA-2cosA)/(1+sin²A+cos²A+2sinA+2sinAcosA+2cosA) ]²

= [( 1+1+2sinA-2sinAcosA-2cosA)/(1+1+2sinA+2sinAcosA+2cosA)]²

= { ( 2(1+sinA) -2cosA(sinA+1) / [ 2(1+sinA) + 2cosA(sinA +1 ) ]}²

= { (2(1+sinA)[1 - cosA] /[2(1+sinA )(1 + cosA )] }²

= [ ( 1 - cosA ) / ( 1 + cosA ) ]²

= RHS