Age-based funds have traditionally been thought of as retirement funds. However, there has been a surge of popularity of their use in the 529 plans as well. A 529 plan is a mutual fund set up for college savings. As with retirement funds, the 529 fund changes its risk as the beneficiary of the money ages.
The radian is a unit of angular measure defined such that an angle of one radian subtended from the center of a unit circle produces an arc with arc length 1. A full angle is therefore radians, so there are per radians, equal to or 57./radian. Similarly, a right angle is radians and a straight angle is radians. for measured in radians. Unless stated otherwise, all angular quantities considered in this work are assumed to be specified in radians.
D[in cm] = [Earth-Sun distance in cm]/[parallax in radians] Astronomers usually say the Earth-Sun distance is 1 astronomical unit, where 1 au = 1.5E13 cm, and measure small angles in arc-seconds. [Note that 1.5E13 is computerese for 15,000,000,000,000] One radian has 648000/pi arc-seconds.