What are angles a, b,c, d ?

Which facts are true for the graph of the function below? check all that apply. f(x) = log8 x

What is sin 7x/4 ? i need on this urgent trig

In right ∆abc shown below, the midpoint of hypotenuse ac is located at d and segment bd is drawn.if ab = 12 and bc = 16, then explain why bd = 10. hint: consider what you know about the diagonals of a rectangle.