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Pls pls pls pls pls pls
I request u to pls answer this question
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Pls answer step wise .

Solution,
Given,

• A concave mirror is being used as a shaving mirror.
• Object distance, u = -45 cm
• Lateral magnification, M = 3

Now,
Lateral magnification, M, is defined as:
$$\begin{gathered} M=\frac{Image height \left(h_i\right)}{object height \left(h_f\right)}=-\frac{image dis\tan ce \left(v\right)}{object dis\tan ce \left(u\right)} \\ 3=-\frac{v}{-45} \\ v=135 cm \end{gathered}$$

​​​​​​Let f be the focal length of the mirror.
Using mirror equation,
$$\begin{gathered} \frac{1}{v}+\frac{1}{u}=\frac{1}{f} \\ \frac{1}{f}=\frac{1}{135}+\frac{1}{-45}=\frac{1}{135}-\frac{1}{45}=\frac{1-3}{135}=\frac{-2}{135} \\ f=-\frac{135}{2}cm=-67.5cm \\ Thus, the radius of curvature of the mirror is R=2f=2\times 67.5=135 cm \end{gathered}$$

The image is virtual, erect and magnified.