1. **State the problem:** Calculate the value of the expression $$\sin(-\pi) - 7\sin^2\left(\frac{\pi}{4}\right)$$. 2. **Recall important formulas and values:** - $$\sin(-x) = -\sin(x)$$ (sine is an odd function). - $$\sin(\pi) = 0$$. - $$\sin\left(\frac{\pi}{4}\right) = \frac{\sqrt{2}}{2}$$. 3. **Evaluate each term:** - $$\sin(-\pi) = -\sin(\pi) = -0 = 0$$. - $$\sin^2\left(\frac{\pi}{4}\right) = \left(\frac{\sqrt{2}}{2}\right)^2 = \frac{2}{4} = \frac{1}{2}$$. 4. **Substitute values back into the expression:** $$\sin(-\pi) - 7\sin^2\left(\frac{\pi}{4}\right) = 0 - 7 \times \frac{1}{2} = -\frac{7}{2}$$. 5. **Final answer:** $$\boxed{-\frac{7}{2}}$$