Concave mirror positioning help

[I_LuV_FiZiX]

Homework Statement

A concave shaving mirror has a radius of curvature of 40 cm. It is positioned so that the (upright) image of a man's face is 3.30 times the size of the face. How far is the mirror from the face?

Homework Equations

M = Si/S 1/S + 1/Si = 2/R

The Attempt at a Solution

I have 2 equations with 2 unknowns. I isolated Si in the first one and substituted this expression into equation 2 to find S. I get an answer of 26.1cm.

The computer keeps telling me I'm wrong though. Could someone check my math or tell me if my equation setup is correct?

 

[I_LuV_FiZiX]

oops never mind i got it... 13.94cm

 

[thomate1]

As a scientist, it is important to always double check your calculations and equations to ensure accuracy. In this case, your equation setup is correct, but your calculations may have an error. I would suggest checking your work again and making sure you are using the correct values for the radius of curvature and the magnification (3.30 times the size of the face). If you are still getting a different answer, it may be helpful to consult with a classmate or your teacher for assistance. Additionally, you can also use online resources or formula solvers to confirm your answer. Remember, in science, it is important to always validate your results and seek help when needed.