A concave spherical mirror can be used to

project an image onto a sheet of paper, allow-

ing the magnified image of an illuminated real

object to be accurately traced.

a) If you have a concave mirror with a focal

length of 12 cm, where would you place a

sheet of paper so that the image projected

onto it is twice as far from the mirror as the

object is? Answer in units of cm.

Okay. So I got it down to:

1/f = 1/(2p) + 1/p

which is:

1/12 = p/2 + 1/p

I'm pretty sure you just need to solve for "p" and then "q" would be twice of "p".

"p" = distance of object from mirror

"q" = distance of image from mirror

How do I solve for "p"? I can't believe I forgot how to do this. T_T