Why does Lear respond so angrily to Cordelia

Read Act 1, scene 1 in King Lear. Ed. Michael Best. Internet Shakespeare Editions. University of Victoria, 29 Nov. 2013. Web. 8 Jun. 2016. Click here for a list of the characters.

Q:

In Act 1, scene 1, why does Lear respond so angrily to Cordelia?