Simplify. sin(5π/12)cos(π/12)+cos(5π/12)sin(π/12)=

1 answer

We can simplify the expression \(\sin\left(\frac{5\pi}{12}\right)\cos\left(\frac{\pi}{12}\right) + \cos\left(\frac{5\pi}{12}\right)\sin\left(\frac{\pi}{12}\right)\) by recognizing that it resembles the sine angle addition formula:

\[ \sin(a + b) = \sin(a)\cos(b) + \cos(a)\sin(b) \]

In this case, we can let:

  • \(a = \frac{5\pi}{12}\)
  • \(b = \frac{\pi}{12}\)

Then the expression can be written as:

\[ \sin\left(\frac{5\pi}{12} + \frac{\pi}{12}\right) \]

Now, we need to compute \(\frac{5\pi}{12} + \frac{\pi}{12}\):

\[ \frac{5\pi}{12} + \frac{\pi}{12} = \frac{5\pi + \pi}{12} = \frac{6\pi}{12} = \frac{\pi}{2} \]

Thus, the expression simplifies to:

\[ \sin\left(\frac{\pi}{2}\right) \]

Knowing that \(\sin\left(\frac{\pi}{2}\right) = 1\), we conclude:

\[ \sin\left(\frac{5\pi}{12}\right)\cos\left(\frac{\pi}{12}\right) + \cos\left(\frac{5\pi}{12}\right)\sin\left(\frac{\pi}{12}\right) = 1 \]

Thus, the simplified expression is:

\[ \boxed{1} \]