Physics help please?

A concave shaving mirror has a radius of curvature of 25.0 cm. For each of the following cases, find the magnification and determine whether the image formed is real or virtual and upright or inverted.


(a) an upright pencil placed 46.0 cm from the mirror








virtual and inverted


virtual and upright


real and inverted


real and upright





(b) an upright pencil placed 25.0 cm from the mirror








virtual and upright


virtual and inverted


real and inverted


real and upright





(c) an upright pencil placed 8.0 cm from the mirror








real and inverted


virtual and inverted


real and upright


virtual and upright

Physics help please?
f = R/2 =12.5cm;


(a) 1/s +1/s’ =1/f;


s’=1/(1/f –1/s) = 1/(1/12.5 -1/46)=17.16cm;


m=-s’/s = -17.16/46 =-0.37;


real inverted;


(b) 1/s +1/s’ =1/f;


s’=1/(1/f –1/s) = 1/(1/12.5 -1/25)=25cm;


m=-s’/s = -1;


real inverted;


(c) 1/s +1/s’ =1/f;


s’=1/(1/f –1/s) = 1/(1/12.5 -1/8)=-22.22cm;


m=-s’/s = 22.22/8 =2.77;


virtual upright;