No, your example is concave. The above posters were referring to functions with positive second derivative.
The mnemonic I was taught is “conve^x like e^x”
I learned “concave up” like e^x and “concave down” like log x.
How in jubbly jibblies did this get voted down? The obvious way to resolve the ambiguity in “convex” and “concave” for functions is to also specify a direction.
It might be downvoted because it specifies “concave up” and then “concave down”.
No, your example is concave. The above posters were referring to functions with positive second derivative.
The mnemonic I was taught is “conve^x like e^x”
I learned “concave up” like e^x and “concave down” like log x.
How in jubbly jibblies did this get voted down? The obvious way to resolve the ambiguity in “convex” and “concave” for functions is to also specify a direction.
It might be downvoted because it specifies “concave up” and then “concave down”.