Question

sin a, tg a, ctg a, если 0<a<П/2, cos a=3/5 - вычислить

Answer 1

$0<a<frac{pi}{2} ; cosa=frac{3}{5}\ \ sin^2a+cos^2a=1\ sin^2a=1-cos^2a\ sin^2a=1-frac{9}{25}\ sin^2a=frac{16}{25}\ sina=frac{4}{5}\ \ tga=frac{sina}{cosa}\ \ tga=frac{4*5}{5*3}\ \ tga=frac{4}{3}\ \ ctg=frac{3}{4}$

Answer 2

sin^2A=1-cos^2A
sin^2A=1-(3/5)^2
sin^2A=1-9/25
sin^2A=16/25
sin2A=4/5
tgA=4*5/5*3

tgA=4/3

ctgA=3/4