Tính giá trị của biểu thức lượng giác, biết a) sin(a-b) , cos(a+b) , tan(a+b) khi sin a = 8/17 , tan b = 5/12 b) cos(π/3-a) khi sin a = -12/13 , 3π/2 < a < 2π c) tan(a+π/3) khi sin a = 3/5 , π/2 < a < π

How to determine whether two known pairs of points are on the same line.

The diagonals of a quadrilaretral intersect at (-1,4). one of the sides of the quadrilateral is bounded by (2,7) and (-3,5) determine the coordinates of the other side in order for the quadrilaretral to be a square.

Abag of jelly beans contain 13 pink, green, 20 yellow, 10 black, 7 red, and 11 orange jelly beans. approximately what percent of the jelly beans are pink and yellow?