A meniscus lens is one that has one concave surface, and one convex

surface. A positive meniscus lens is a converging lens. A negative

meniscus lens is a diverging lens.

$($a$)$ Sketch a positive meniscus lens assuming light hits concave side

first. Indicate which sides are concave and convex and which are

$R_1$ and $R_2$ and whether $R_1$ and $R_2$ are positive or negative.

$($b$)$ Determine the condition on $|\frac{R_1}{R_2}|$ in order to produce a positive

meniscus lens, assuming a glass lens in air and light hits concave

side first.