What is the concavity of a linear function?

1 Answer
Jun 10, 2018

Here's an approach...

Explanation:

Let's see...

A linear is in the form f(x)=mx+bf(x)=mx+b where mm is the slope, xx is the variable, and bb is the y-intercept. (You knew that!)

We can find the concavity of a function by finding its double derivative (f''(x)) and where it is equal to zero.

Let's do it then!

f(x)=mx+b

=>f'(x)=m*1*x^(1-1)+0

=>f'(x)=m*1

=>f'(x)=m

=>f''(x)=0

So this tells us that linear functions have to curve at every given point.

Knowing that the graph of linear functions is a straight line, this does not make sense, does it?

Therefore, there is no point of concavity on the graphs of linear functions.