{"id":3368,"date":"2025-11-15T12:34:19","date_gmt":"2025-11-15T03:34:19","guid":{"rendered":"https:\/\/frankyoshida.com\/experts-at-community\/?p=3368"},"modified":"2025-11-15T12:35:30","modified_gmt":"2025-11-15T03:35:30","slug":"%e3%80%90mathematics%e3%80%91high-school-math-for-global-business-derivatives-and-hydrofoil-speed-calculations","status":"publish","type":"post","link":"https:\/\/frankyoshida.com\/experts-at-community\/?p=3368","title":{"rendered":"\u3010Mathematics\u3011High School Math for Global Business! Derivatives and Hydrofoil Speed Calculations (1)"},"content":{"rendered":"

Hello, this is Frank.<\/p>\n

From today, I will introduce practical math concepts useful in global business. These are at a fundamental level, but I hope they will also help you in learning English alongside math.<\/p>\n

\n

This time, we tackle a problem involving derivatives<\/strong> and calculating the speed of a hydrofoil<\/strong> in still water.<\/p>\n

Let’s start with my favorite topic, derivatives. As a humanities major, I chose a fundamental question. Why not give it a try?<\/p>\n

\u3010Questions\u3011<\/h3>\n

(1) What is the derivative of \\(y = x^{3} + 6\\)?
\n(2) A hydrofoil goes 15 km upstream in 15 minutes. The speed of the stream is 5 km\/h. What is the speed of the hydrofoil in still water?
\n<\/font><\/strong><\/p>\n

Here are the solutions to the questions above.<\/strong><\/p>\n

\u3010Answers\u3011<\/h3>\n

(1) Using the formula \\(\\frac{d}{dx}(x^{n}) = nx^{n-1}\\), we get:
\n\\(\\frac{d}{dx}(x^{3} + 6) = 3x^{2} + 0 = 3x^{2}\\)<\/p>\n

(2) “15 km upstream in 15 minutes” means the hydrofoil would cover 60 km in 1 hour.
\nSpeed of the stream = 5 km\/h.
\n\u2234 Speed of the hydrofoil in still water = 60 + 5 = 65 km\/h.<\/p>\n

\n

How was that? I created these problems and solutions based on international math websites and textbooks, such as High School Math Revisited<\/a>. Numbers, conditions, and explanations have been adjusted to ensure originality.<\/p>\n

Stay tuned for future installments! b\uff3e\uff3e)<\/p>\n

Learn more about Practical Math for Global Business<\/a> b\uff3e\uff3e)<\/p>\n

Reference:<\/strong> High School Math Revisited<\/a> by Kazuo Takahashi, Nihon Jitsugyo Publishing<\/p>\n

For those interested in my online English lessons, please visit here<\/a>.<\/p>\n

We strive to provide accurate and up-to-date information on this site, but cannot guarantee completeness or take responsibility for any discrepancies.<\/p>\n

\"\"<\/a>\"\"<\/p>\n

\n

For those curious about my publications, please visit my Amazon Author Page<\/a>.<\/p>\n

Back to Genre\uff1a>Here<\/a><\/p>\n

\n

Need a break? Why not check out my daughter\u2019s YouTube channel, asobifantasia<\/a>.
\nWe\u2019d be so happy if you subscribed!<\/p>\n

Currently, I’m participating in the popular blog rankings.
\nToday’s ranking for [masona\uff5cTop Blog Digest] is?<\/p>\n

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