Write the lens maker's formula.

Obtain the lens makers formula using the expression $\frac{{\mathrm{n}}_2}{\mathrm{v}}-\frac{{\mathrm{n}}_1}{\mathrm{u}}=\frac{{\mathrm{n}}_2-{\mathrm{n}}_1}{\mathrm{R}}$ Here the ray of light propagating from a rarer medium of refractive index ${\mathrm{n}}_1$ to a denser medium of refractive index ${\mathrm{n}}_2$ is incident on the convex side of spherical refracting surface of radius of curvature R.