Jika sin a = 3/10 tentukan cos a

sin a = y/r
3/10 = y/r

Maka y = 3, r = 10
x = √r²-y²
= √100-9 = √91

cos a = x/r = √91/10
tan a = y/x = 3/√91 = 3√91/91

Semoga membantuu :)