diketahui sin A=0,75 cos B=0,8 ,jika sudut A dan B sudut lancip, tentukan nilai dari cos A sin B

cosA = 1/sinA = 1/0,75
= 1/75/100 -> 1/1 x 100/75 = 4/3

sinB = 1/cosB = 1/0,8 = 1/8/10 = 1/1 x 10/8 = 10/8 = 5/4

Bab Trigonometri
Matematika SMA Kelas X

sin A = 0,75 = 3/4 = y/r

tripel pitagoras
x = √(r² - y²)
x = √(4² - 3²)
x = √(16 - 9)
x = √7

cos B = 0,8 = 4/5 = x/r

tripel pitagoras
y = √(r² - x²)
y = √(5² - 4²)
y = √(25 - 16)
y = 3

cos A . sin B
= (√7)/4 . 3/5
= (3/20) √7