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If y = x sinx, find \(\frac{dy}{dx}\)

If y = x sinx, find \(\frac{dy}{dx}\)
Take Free Practice Test On 2026 JAMB UTME, Post UTME, WAEC SSCE, GCE, NECO SSCE
  • A Sin x - x cosx
  • B Sinx + x cosx
  • C Sinx - cosx
  • D Sinx + cosx
Correct Answer: Option B
Explanation:
If y = x sinx, then
Let u = x and v = sinx
\(\frac{du}{dx}\) = 1 and \(\frac{dv}{dx}\) = cosx
Hence by the product rule,
\(\frac{dy}{dx}\) = v \(\frac{du}{dx}\) + u\(\frac{dv}{dx}\)
= (sin x) x 1 + x cosx
= sinx + x cosx

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