A - area of a trapezoid;
a, b - two bases.
A = h * ( a + b ) / 2 / * 2 ( we have to multiply both sides by 2 )
2 A = h *( a + b )
2 A = h a + h b
h b = 2 A - h a
b = ( 2 A - h a ) / h
b = 2 A/h - a
Answer: D )
<span>A. cos(x) = cos(-x) [correct, since cos(x) is an even function]
B. Since the cosine function is even, reflection over the x-axis [y-axis] does not change the graph. [false]
C. cos(x) = -cos(x) [ false]
D. The cosine function is odd [even], so it is symmetrical across the origin. [false]</span>
