Summation calculus differentiation problem

Question

I am new in calculus. So it will be helpful if anyone solve it and give some hint how it works.

$$E = \frac{1}{3} \sum_{i=1}^3 (mx_i+c-y_i)^2$$

Then what will be $\frac{dE}{dm}$ and $\frac{dE}{dc}$?

Thanks.

Answer 1

\begin{align} \frac{dE}{dm} & =\sum_{i=1}^3 \frac{2}{3}x_i(mx_i+c-y_i) \\ \frac{dE}{dc} & = \sum_{i=1}^3 \frac{2}{3}(mx_i+c-y_i) \end{align}