Web Browser and server using ECDHE_RSA cypher suite, then what is the use of X.509 certificate public key for?

User Crover has given a very great explanation for this question:
RSA or ECDHE for x.509 certificates-what does each do?
I have one question to Crover and/or any other member.
What I understand from the Crover’s answer, if client (a Web Br… Continue reading Web Browser and server using ECDHE_RSA cypher suite, then what is the use of X.509 certificate public key for?