Answer:
A, B and C
Step-by-step explanation:
A. Adding another researcher to provide ratings will make the study less biased.
B. A quiz or exam will show which students have a better understanding of the math material. Better quiz or exam results show that the site is more effective for a student with or without the supplemental instruction.
C. Having a greater sample size is better because a greater scope of students is covered. Different students have different abilities and learning preferences.
Answer:
y = 4 sin( 0.5t - 
) - 2
y = a sin ( 2t - 
) + 2
Step-by-step explanation:
In the first question,
amplitude = 4
Period = 
phase shift = 
Vertical shift = -2
Angular velocity , w = 
Here, w = 
= 0.5
The general equation of a wave is
y = a sin( wt + ∅ )
Putting above values in the equation,
y = 4 sin( 0.5t - ) - 2
In the second question,
Amplitude is not given so we will take it as a.
time period = 
w = 2
Phase shift =
Vertical shift = 2
The equation is
y = a sin ( 2t - ) + 2
Answer:
12.7
Step-by-step explanation:
you have to turn 4/5 into a decimal then subtract that from 13.50
Answer:
C
Step-by-step explanation:
The vertex form of the equation of a circle is 
where (h,k) is the center of the circle and r is the radius. This means that for the circle with center (-3,1) and radius 5 substitute into the vertex form these values. Substitute h = -3, k= 1, and r = 5. The equation becomes 
. This simplifies to 
. The solution is C.
