## Trigonometry (10th Edition)

given the equation $\sin^{2}180+\cos^{2}180$, it should be noted that $\sin180$ is 0 and therefore squaring it also results in a 0. $\cos180$ on the other hand, is equal to -1 and squaring that value would give 1, therefore $\sin^{2}180+\cos^{2}180=1$ In math terms: $\sin^{2}180+\cos^{2}180 = 0^{2} + -1^{2}$ $=1$