Find the exact value of the expression.cos 40° cos 20° - sin 40° sin 20°
A. 
B. 
C. 
D. 
Answer: D
Mathematics
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Find the vertex for the parabola whose equation is given.y = 6x2 + 12x - 9
A. (1, 9) B. (2, 39) C. (-1, -15) D. (-2, 3)
Mathematics
- 10 = -6
A. -12 B. 14 C. -14 D. 12
Mathematics
Simplify the expression by removing parentheses and combining like terms.-2(4m + 5) + 2(3m - 4)
A. -2m + 2 B. 7m - 18 C. -2m - 18 D. -2m + 1
Mathematics
Evaluate the integral.
Mathematics