Which of the following relations is a function?

a {(2, 2), (3, 3), (4, 4), (5, 5)}
b {(2, 1), (2, 3), (3, 6), (3, 7)}
c {(3, 5), (4, 9), (4, 11), (5, 14)}
d {(4, 8), (6, 6), (8, 4), (8, 2)}

  21.3

step-by-step explanation:

multiplying the given equation by c/sin(25°), we get

  c = 9/sin(25°) ≈ 21.2958 ≈ 21.3

we assume "c" is the length of ab, the side opposite angle c in triangle abc.

first, you divide the triangle in two, tô form a retangle triangle. after, using pythagoream theorem:

18^2 = 14^2 + (x/2)^2

(x^2/4) + 196 = 324

x^2/4 = 324 - 196

x^2/4 = 128

x^2 = 512

x = √512

x = √2^9

x = 16√2 cm

i hope i you.