Use a double-angle identity to find the exact value of the expression.2 cos2 22.5° - 1
A. 
B. 
C. 
D. 
Answer: B
Mathematics
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The position vector of a particle is r(t). Find the requested vector.The velocity at t = 2 for r(t) = (4 - 5t2)i + (4t + 9)j - e-2tk
A. v(2) = -20i + 4j - 2e-4k B. v(2) = -10i +4j + 2e-4k C. v(2) = 20i + 4j + 2e-4k D. v(2) = -20i + 4j + 2e-4k
Mathematics
Determine an appropriate viewing window for the given function and use it to display its graph.f(x) = x4 - 5x3 + 12x2 + x - 21
A. 
B. 
C. 
D. 
Mathematics
Write the word phrase as an algebraic expression. Use x to represent the unknown number in the phrase.16 times the difference of 6 and a number
A. 16x - 6 B. 6 - 16x C. 16(6 - x) D. 6(16 - x)
Mathematics
Round the mixed number to the nearest integer.-6
A. -6
B. -7
C. -6
D. 7
Mathematics