Prove the identity.
- 
= cos2 2x - sin2 2x
What will be an ideal response?
Answers may vary. One possible solution is:
- 
= cos 3x cos x - sin 3x sin x = cos (3x + x) = cos 4x = cos2 2x - sin2 2x.
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Translate to a variable expression. Use n for the variable unless otherwise stated.three subtracted from the quotient of nine and some number
A. 3 - 
B. 3 - 
C. 
- 3
D. 
- 3
Find the indicated angle.Find the supplement of 131°.
A. 229° B. 49° C. 139° D. not possible
Find the matrix product AB, if it is defined.A = 
, B = 
.
A. 
B. 
C. 
D. 
Solve the problem.A computer virus begins to spread among the computers in a large corporation. The percent of the computers that are infected is approximately 
where t is the number of hours that have elapsed since the first computer contracted the virus. Find the instantaneous rate of change of the percent of computers infected at 
hours.
A. 17%/hour B. 20%/hour C. 12%/hour D. 23%/hour