Simplify the expression:? (sin^2(pi/2+alpha)-cos^2(alpha-pi/2))/(tg^2(pi/2+alpha)-ctg^2(alpha-pi/2))sin2(π2+α)cos2(απ2)tg2(π2+α)ctg2(απ2)

(sin^2(pi/2+alpha)-cos^2(alpha-pi/2))/(tg^2(pi/2+alpha)-ctg^2(alpha-pi/2))sin2(π2+α)cos2(απ2)tg2(π2+α)ctg2(απ2)

1 Answer
Apr 10, 2017

(sin^2(pi/2+alpha)-cos^2(alpha-pi/2))/(tan^2(pi/2+alpha)-cot^2(alpha-pi/2))sin2(π2+α)cos2(απ2)tan2(π2+α)cot2(απ2)

=(sin^2(pi/2+alpha)-cos^2(pi/2-alpha))/(tan^2(pi/2+alpha)-cot^2(pi/2-alpha))=sin2(π2+α)cos2(π2α)tan2(π2+α)cot2(π2α)

=(cos^2(alpha)-sin^2(alpha))/(cot^2(alpha)-tan^2(alpha))=cos2(α)sin2(α)cot2(α)tan2(α)

=(cos^2(alpha)-sin^2(alpha))/(cos^2(alpha)/sin^2(alpha)-sin^2(alpha)/cos^2(alpha))=cos2(α)sin2(α)cos2(α)sin2(α)sin2(α)cos2(α)

=(cos^2(alpha)-sin^2(alpha))/((cos^4(alpha)-sin^4(alpha))/(sin^2(alpha)cos^2(alpha)))=cos2(α)sin2(α)cos4(α)sin4(α)sin2(α)cos2(α)

=(cos^2(alpha)-sin^2(alpha))/(cos^4(alpha)-sin^4(alpha))xx(sin^2(alpha)cos^2(alpha))/1=cos2(α)sin2(α)cos4(α)sin4(α)×sin2(α)cos2(α)1

=(cos^2(alpha)-sin^2(alpha))/((cos^2(alpha)-sin^2(alpha))(cos^2(alpha)+sin^2(alpha))xx(sin^2(alpha)cos^2(alpha))/1=cos2(α)sin2(α)(cos2(α)sin2(α))(cos2(α)+sin2(α))×sin2(α)cos2(α)1

=sin^2(alpha)cos^2(alpha)=sin2(α)cos2(α)