Computers are believed to be smarter than humans by several scientists in no time.
You have used an incorrect verb form (are believed - past participle) in this sentence. The expression "in no time" indicates that the action will take place in the future. Please consider revising :)
From my perspective, although technology can do most kinds of work, it does not have enough cognitive and mental abilities to analyze sophisticated situations.
This is your thesis statement; however, I have found several issues. Firstly, you have not answered the question correctly. The question, " To what extent do you agree or disagree with this statement?" means how FAR you agree or disagree with the given statement ( I agree, I strongly agree, I disagree, I strongly disagree, etc.). Secondly, you have not clearly stated your opinion. The word "technology" is a general term which means it also includes other tools; thus, it does not specifically refer to computers. Thirdly, I would like to emphasize that the pronoun "it" refers to technology, not to computers; hence, you have to consider correct word choice as well to improve this sentence.