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For all values of A ,B ,Ca n dP ,Q ,R sh...

For all values of `A ,B ,Ca n dP ,Q ,R` show that `|"cos"(A-P)"cos"(A-Q)"cos"(A-R)"cos"(B-P)"cos"(B-Q)"cos"(B-R)"cos"(C-P)"cos"(C-Q)"cos"(C-R)|=0`

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`|{:(cos(A-P),,cos(A-Q),,cos(A-R)),(cos(B-P),,cos(B-Q),,cos(B-R)),(cos(C-P),,cos(C-Q),,cos(C-R)):}|`
`|{:(cos A cos P + sin A sin P,,cos A cos Q +sin A sin Q,,cos A cos R + sin A sin R),(cos B cos P +sin B sin P,,cos B cos Q+ sin C sinQ,,cos B cos R+sinB sinR),(cos C cos P+ sin C sin P,,cos C cos Q+sin C sin Q,,cosCcosR+sinCsinR):}|`
`|{:( cos A,, sin A,,0),(cos B,,sinB,,0),(cos C,,sin C,,0):}| |{:(cos P,,sin P,,0),(cos Q,,sin Q,,0),(cos R,,sin R,,0):}|`
`=0xx0=0`
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