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Question
Without using trigonometric identity , show that :
`sin(50^circ + θ) - cos(40^circ - θ) = 0`
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Solution
`sin(50^circ + θ) - cos(40^circ - θ) = 0`
`sin(50^circ + θ) = cos[90^circ - (50^circ + θ)] = cos(40^circ - θ)`
`sin(50^circ + θ) - cos(40^circ - θ)`
= `cos(40^circ - θ) - cos(40^circ - θ)`
= 0
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