#### Answer

At the given point of the graph the instantaneous rate of change, the slope of the tangent and the value of the derivative are equal to each other.

#### Work Step by Step

The instantaneous rate of change at $a$ is
$$\lim_{x\to a}\frac{f(x)-f(a)}{x-a}.$$
The slope of the tangent at the given point $(a,f(a))$ is
$$m_{tan}=\lim_{x\to a}\frac{f(x)-f(a)}{x-a}.$$
The value of the derivative of the function $f$ at the point $a$ is given by deffinition as
$$f'(a)=\lim_{x\to a}\frac{f(x)-f(a)}{x-a}.$$
We see that at the given point of the graph the instantaneous rate of change, the slope of the tangent and the value of the derivative are equal to each other.