Question

Tg30 x ctg60 + tg60 x ctg30 = ?
Sa-mi explice cineva de ce tg30 grade devine 1/3 in loc de radical din 3/3 ?
Va rog!!!

Answer 1

[tex]\it ctg 60^0 =tg(90^0-60^0)=tg30^0 \\\;\\ \it ctg 30^0 =tg(90^0-30^0)=tg60^0[/tex]

Expresia devine:

$\it (tg 30^0)^2 +(tg 60^0)^2 = \left(\dfrac{\sqrt3}{3}\right)^2+ (\sqrt3)^2 = \dfrac{3}{9} +3 = \dfrac{1}{3} +3 =\dfrac{10}{3}$