Răspunsuri

2014-05-08T16:27:01+03:00
CosB =  \frac{AB^2  +  BC^2 - AC^2}{2AB*BC}= \frac{81+144-49}{y} = \frac{176}{216}= 0.814
sinB = √(1-cos²B) = √(1-0.665) =√0.335=0.578
tgB =  \frac{sinB}{cosB} = \frac{0.578}{0.814} = 0.71
ctgB =  \frac{1}{0.71} = 1.408