You can use Matlab to determine the word that appears most frequently in a paragraph using the following steps:

1. Convert the paragraph to lowercase letters to avoid distinguishing between uppercase and lowercase words.

2. Use the split function to split the paragraph into individual words.

3. Use the unique function to get a list of unique words in the paragraph.

4. Use a loop to iterate through the unique words and count how many times each word appears in the paragraph.

5. Find the word that appears most frequently by using the max function to find the maximum count and the find function to find the index of the word with the maximum count.

Here is the Matlab code to accomplish these steps:

% Sample paragraph
paragraph = "This is a sample paragraph. It contains multiple sentences, and each sentence has multiple words.";

% Convert paragraph to lowercase
paragraph = lower(paragraph);

% Split paragraph into individual words
words = split(paragraph);

% Get unique words
uniqueWords = unique(words);

% Count how many times each word appears
counts = zeros(size(uniqueWords));
for i = 1:length(uniqueWords)
    counts(i) = sum(ismember(words, uniqueWords{i}));
end

% Find word that appears most frequently
[maxCount, maxIndex] = max(counts);
mostFrequentWord = uniqueWords{maxIndex}

In this example, the most frequent word in the paragraph is "multiple", which appears twice.