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Show that |sin10o-cos10osin80ocos80o|=1...

Show that `|sin10o-cos10osin80ocos80o|=1`

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We have to prove that `|(sin10^o,-cos10^o),(sin80^o,cos80^o)|=1`
Then
Let |A|=`|(sin10^o,-cos10^o),(sin80^o,cos80^o)|`
`=|(sin10^o,-cos10^o),(cos10^o,sin10^o)|`
`=sin^(2)10^(o)+cos^(2)10^o`
`=1`
As `sin^(2)x^(o)+cos^(2)x^o =1.`
`implies |(sin10^o,-cos10^o),(sin80^o,cos80^o)|=1`
...
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