An inflection point is a point on a curve at which the sign of the curvature (i.e., the concavity) changes. Inflection points may be stationary points, but are not local maxima or local minima. For example, for the curve plotted above, the point is an inflection point. The first derivative test can sometimes distinguish inflection points from extrema for differentiable functions . The second derivative test is also useful. A necessary condition for to be an inflection point is . A sufficient condition requires and to have opposite signs in the neighborhood of (Bronshtein and Semendyayev 2004, p. 231).
Rice vermicelli are thin rice-flour noodles common in Chinese, Thai, Vietnamese, and other Southeast Asian cuisines, where they are often used in stir-fries, soups, spring rolls, and salads. Don't confuse rice vermicelli with cellophane noodles, another thin Asian noodle that's made with mung bean starch.
When they are completely limp, give them a taste to see if theyâre cooked through. The thread-like vermicelli noodles used in spring rolls will cook through in just a few minutes. The flat rice noodles might take upwards of ten minutes depending on thickness. Pay attention and test the noodles frequently because theyâll become mushy if they overcook. Once the noodles are tender, drain them and run them under cool water to stop the cooking.