Question:medium

$$ \int_{-\pi/4}^{\pi/4} \sin^{103} x \cos^{101} x \, dx = ? $$

Show Hint

Whenever you see a symmetric interval like $[-a, a]$, always check if the function is odd. It often turns complex-looking trigonometric powers into a simple answer of zero.
Updated On: Apr 29, 2026
  • $\left( \frac{\pi}{4} \right)^{103}$
  • $\left( \frac{\pi}{4} \right)^{101}$
  • $2$
  • 0
Show Solution

The Correct Option is D

Solution and Explanation

To solve the integral \(\int_{-\pi/4}^{\pi/4} \sin^{103} x \cos^{101} x \, dx\), we need to analyze the symmetry properties of the integrand.

The given integral is:

\(I = \int_{-\pi/4}^{\pi/4} \sin^{103} x \cos^{101} x \, dx\)

Notice that \(\sin^{103} x\) is an odd function, and \(\cos^{101} x\) is an odd function because any power of cosine for odd numbers retains the odd nature. Thus, their product, \(\sin^{103} x \cos^{101} x\), is an odd function.

An odd function is defined by the property \(f(-x) = -f(x)\).

The integral of an odd function over a symmetric interval \([-a, a]\) is zero:

\(\int_{-a}^{a} f(x) \, dx = 0\) for odd \(f(x)\).

 

Therefore, since we are integrating an odd function over the symmetric interval \([-π/4, π/4]\), the integral evaluates to:

\(I = 0\)

Hence, the correct answer is 0.

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