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Prove that: cos^(2)48^(@)-sin^(2)12^(@...

Prove that:
`cos^(2)48^(@)-sin^(2)12^(@)=(sqrt(5)+1)/(8)`

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Given ,
`cos^(2)48^(@)−sin^(2)12^(@)`
Using formula,
`cos^2A-sin^2B=cos(A+b)cos(A-B)`
`=>cos(48+12)^(@)cos(48−12)^(@)`
`=>cos(60^(@))cos(36^(@))`
`=>(1/2)​×(sqrt(5)+1)/4`
`=>(sqrt(5)+1)/8`
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