Identify the equation as either an identity or not.cos2x + cos2y = cos (x + y) cos (x - y)
A. Not an identity
B. Identity
Answer: A
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Find the coordinates of the centroid of the given figure. Each region is covered by a thin, flat plate.The region bounded by the parabola x = y2 and the line x = 9
A. (9, 0)
B. 
C. 
D. 
Provide an appropriate response.The table shows the number of pupils per teacher in selected counties in a certain state. 
Which counties have a figure that is at most 14.7?
A. Dixson, Hendricks, Putnum B. Addison, Cumberland, Kendall C. Addison, Branson, Cumberland, Kendall D. Branson, Dixson, Hendricks, Putnum
Solve.A plane makes a 240-mile trip against a head wind in 1 hour and 30 minutes and returns, with a tail wind of the same speed, in 1 hour. What is the speed of the wind?
A. 200 mph B. 160 mph C. 80 mph D. 40 mph
Provide the proper response.It can be shown that a hyperbola with center at the origin, foci at 
and 
and equation 
has equation 
Use this result to find an equation of a hyperbola with center at the origin, foci at 
/> and 
and absolute value of the distances from any point of the hyperbola to the two foci equal to 6.
A. 
- 
= 1
B. 
- 
= 1
C. x2 - y2 = 6
D. 
- 
= 1