Question

Упростить.
Sin^2x+cos^2x-2sin^2•3x

Answer 1

$sin^2x+cos^2x-2sin^23x=1-2sin^23x=\\=[, sin^2 alpha =frac{1-cos2 alpha }{2}; ; to ; ; 2sin^2 alpha =1-cos2 alpha , ]=\\=1-(1-cos6x)=cos6x$