Ответы и объяснения

2013-02-26T20:23:44+04:00

cos122=cos(62+60)

cos2=cos(62-60)

1-2cos^2 14=-cos28=-cos(90-62)=-sin62

(cos 122-cos 2)/1-2cos^2 14=(cos(62-60)-cos(62+60))/sin62=2sin62cos60/sin62=2cos60=2*1/2=1