Question 1102963
The apparent magnitude of a star refers to the brightness of the star. 
Objects with lower magnitude appear brighter to the eye than objects with higher magnitude.
 For higher magnitudes a telescope is required.
 However, even a telescope has its limitations. 
The limiting magnitude L of an optical telescope with lens diameter D (in inches) is given by L(D) = 8.8 + 5.1logD.
 Use this function to find the following:
: 
a. Find the limiting magnitude for a telescope with a lens 10 inches in diameter.
 Round to 1 decimal place if needed.
L(d) = 5.1*log(10)
We know the log of 10 is 1, therefore
L = 5.1 amplitude
: 
b. How large a telescope is needed to see a galaxy with magnitude 19?
 Round to the nearest inch if needed.
5.1*log(d) = 19
log(d) = {{{19/5.1}}}
log(d) = 3.7255
Find the antilog
d = 5315 inches or divide by 12 to get 443 ft