Question

Evaluate sinB given that sinA=-1, a=10 and b=4

Answer 1

-2.5

Explanation:

Using the sine rule, a/sinA = b/sinB.

So, sinB = bsinA/a

substituting sinA = -1, a = 10 and b = 4, we have

sinB = 10 × (-1)/4

= -10/4

= -5/2

= -2.5