Answer:
y = -9
Step-by-step explanation:
y2 - y1 / x2 - x1
-9 - (-9) / -3 - 1
0 / -4
y = 0 + b
-9 = b
Hello!
To find cosine, use the formula cos = adjacent / hypotenuse.
According to angle B, adjacent of angle B is side A, and the hypotenuse is side c because the hypotenuse is always opposite the right angle.
Therefore, the cosine of angle B is a/c.