# Is #f(x)=sinx# concave or convex at #x=pi/2#?

##### 1 Answer

See below

#### Explanation:

to even find concavity, you should know what it means by concave up and concave down.

if a functions

graph{y=9x [-10, 10, -5, 5]}

then its concave-Up

if a functions

graph{-27x [-10, 10, -5, 5]}

then its concave-Down

but all of these points and graphs are linear, your looking for an point on an non-linear graph

the second derivative of

here's the graph:

graph{-sin(x) [-10, 10, -5, 5]}

at