Question

вычислите (cos^2альфа-sin^2альфа)^2+4sin^2альфаcos^2альфа

Answer 1

1)

$(cos(alpha)^{2}-sin(alpha)^{2})^{2}+4sin(alpha)^{2}*cos(alpha)^{2} \ \ cos(2alpha)^{2}+4sin(alpha)^{2}*cos(alpha)^{2} \ \ cos(2alpha)^{2}+sin(2alpha)^{2}=1$

2)

$tg(alpha)+ctg(alpha)=tg(alpha)+ frac{1}{tg(alpha)} = frac{tg(alpha)^{2}+1}{tg(alpha)} \ \ frac{ frac{sin(alpha)^{2}}{cos(alpha)^{2}}+1 }{ frac{sin(alpha)}{cos(alpha)} } = frac{ frac{sin(alpha)^{2}+cos(alpha)^{2}}{cos(alpha)^{2}} }{ frac{sin(alpha)}{cos(alpha)} } = frac{1}{cos(alpha)*sin(alpha)} = frac{1}{0,6}= frac{1}{ frac{5}{3} } = frac{5}{3}=1 frac{2}{3}$

Answer 2

Спасибо большое!!!!!!