You measure the apparent brightness of a particular star to be 2.5 x 10-10 watt/m2. A parallax measurement shows the star’s distance to be 42 light-years, or about 4 x 1017 meters. What is the stars luminosity?

2 and 1.

step-by-step explanation:

plug in each answer. 0 doesn't work, 1 does. so does 2. 4 doesn't:

0 = 1 is not true.

2 = 2 is true.

4 = 4 is true.

8 = 16 is not true.

hope this !

since no one answered yet i will give it a shot, not completely sure tho.

i think it should be y=cos(x+2pi), (third answer, answer c)

good luck.

the correct answers are 1, 2, 4, and 5! i just got it right!