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Question
`((sin A- sin B ))/(( cos A + cos B ))+ (( cos A - cos B ))/(( sinA + sin B ))=0`
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Solution
LHS =`((sin A- sin B ))/(( cos A + cos B ))+ (( cos A - cos B ))/(( sinA + sin B ))`
=`((sinA - sin B )( sinA + sinB )+ ( cos A - cosB )( cosA - cosB))/((cos A+ cos B )( sin A+ sinB))`
=` (sin^2 A - sin^2 B + cos^2 A - cos^2 B)/( (cos A + cos B )( sinA + sinB))`
=` 0/((cos A + cos B )( sin A + sinB ))`
=0
=RHS
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Activity:
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= `square (1 - (sin^2theta)/(tan^2theta))`
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= `tan^2theta (1 - (sin^2theta)/1 xx (cos^2theta)/square)`
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