Now lets move on to factorizations that may require two or more techniques. In Exercises 1780, factor completely, or state that the polynomial is prime. Check factorizations using multiplication or a graphing utility. 7y4 14y3 7y2

1 Astronomy Unit 4B Milky Way Galaxy Part 2: The Mass of the Galaxy- We can estimate the mass of the galaxy from the sun’s orbital motion Kepler’s 3 Law applied to the Galaxy is: 3 2 o M = galp o Here, a= the distance to the center of the galaxy, 8.5 kpc or 1.75 AU o The orbital period of the sun around the galaxy is the circumference of its orbit, 2pia, divided by its orbital speed of 220 km/s o It takes the sun 240 million years to orbit the galaxy once Kepler’s Law gives: o M =(gal.75 X 10 AU) / (2.4 X 10 yrs) ) M. = 1.0 X 10 M. 11 o The galaxy contains the equivalent of about 100 billion Suns Mass Beyond the S