A) 1 + tan ^ 2α = sec ^ 2α b)(1 + secx / 1 - secx) = (cosx + 1 / cosx - 1)
1 + sen ^ 2α / cos ^ 2α = sec ^ 2α (1 + 1 / cosx) / (1 - 1 / cosx) = (cos + 1 / cos - 1)
(cos ^ 2α + sen ^ 2α) / cos ^ 2α = sec ^ 2α ((cosx + 1) / cosx) / ((cosx - 1) / cosx) = " " 1 / cos ^ 2α = sec ^ 2α simplificando cosx y cosx sec ^ 2α = sec ^ 2α Resp.
(cosx + 1) / (cosx - 1) = (cosx + 1 / cosx - 1)
c) cosx.
Tgx = senx cosx.
(senx / cosx) = senx
simplificando cosx y cosx
senx = senx Resp.
D) senx.
Secx = tgx senx(1 / cosx) = tgx senx / cosx = tgx tgx = tgx Resp.
E) senx * ctgx = cosx senx * cosx / senx = cosx simplificando senx y senx cosx = cosx Resp.