📝 U Substitution

Q1. When evaluating \(\int 2x \cdot \sqrt{x^2 + 1} \, dx\), which substitution is most appropriate?

💡 Difficulty: easy | ✅ Correct: A

Q2. A particle moves along a line with velocity \(v(t) = 4t \cdot e^{t^2}\). Using a \(u\)-substitution, find the displacement from \(t = 0\) to \(t = 1\). Which substitution should be used?

💡 Difficulty: medium | ✅ Correct: A

Q3. Find the antiderivative of \(\int \frac{5x^4}{\sqrt{x^5 + 3}} \, dx\) using \(u\)-substitution. Which \(u\) is correct?

💡 Difficulty: hard | ✅ Correct: A