Simplify cos(2x)/cos(x)-sin(x). a. 2sin(x)cos(x)/cos(x)-sin(x)
b. 2sin(x)cos(x)/sin(x)-cos(x)
c. cos(x)+sin(x)
d. cos(x)-sin(x)

The median am of triangle ∆abc is half the length of the side towards which it is drawn, bc . prove that triangle ∆abc is a right triangle, and find angle mac and abm