Answer:
in confused on what the question is asking is it multiple questions
Answer:
Options B and D.
Step-by-step explanation:
The general form of sine function

where, |A| is amplitude,
is period,
is phase shift and D is y-intercept.
The general form of cosine function

where, |A| is amplitude,
is period,
is phase shift and D is y-intercept.
In function, 
Amplitude : 
y-intercept : -1
In function, 
Amplitude : 
y-intercept : -1
In function, 
Amplitude : 
y-intercept : 0
In function, 
Amplitude : 
y-intercept : -1
Therefore, the correct options are B and D.
It's C I'm pretty sure and this in English not math
Answer:
If light passes in an angle to a surface with a particular refractive index it refracts. This change in direction is due to a change in velocity. As light , for example, travels from air through water, it slows down, allowing it to continue travelling at a different angle or direction.
Step-by-step explanation: