Use a double-angle identity to find the exact value of the expression.2 cos2 22.5° - 1
A. 
B. 
C. 
D. 
Answer: C
Mathematics
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Graph the integrand and use areas to evaluate the integral.
A. 
B. 98
C. 49
D. 147
Mathematics
Solve, finding all solutions in [0, 2?). Give an exact answer unless indicated otherwise.
= 
A. 
, 
B. 
, 
C. 
, 
D. 
, 
Mathematics
Evaluate the determinant.
A. -144 B. 144 C. -4 D. -12
Mathematics
Match the system of inequalities with the appropriate graph.x + 2y ? 2 x - y ? 0
A. 
B. 
C. 
D. 
Mathematics