Question

Calcule cosseno, tangente do ângulo B dado sen B = 3/5​

Answer 1

sen B = 3/5

sen²B + cos²B = 1

(3/5)² + cos²B = 1

cos²B = 1 - 9/25

cos²B = 16/25

cosB =  \sqrt{ \frac{16}{25} }  

cosB = 4/5

tgB = senB / cosB

tgB = 3/5 / 4/5

tgB = 15/20  = 3/4