Final answer:
The second-person point of view in the excerpt is indicated by direct references to 'you,' suggesting the reader as the subject, as seen in phrasings like 'Do not be disheartened' and 'it will pay you to spare no pains to conquer it.'
Step-by-step explanation:
The parts of the excerpt from “The Art of Public Speaking” by Dale Carnegie that indicate it is written using second-person point of view are: “Do not be disheartened if at first you suffer from stage-fright” and “it will pay you to spare no pains to conquer it”. These sections directly address the reader as “you”, which is a characteristic of the second-person point of view. In contrast to first-person which uses pronouns like “I” and “me”, and third-person which uses pronouns such as “he”, “she”, “they”, or names, the second-person uniquely engages the reader by speaking directly to them with the pronoun “you.”