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