Mathematics

The key here is the Pythagorean identity $\sin^2\theta + \cos^2\theta = 1$, which connects sine and cosine for any angle. Since you know $\sin\theta$, you can substitute it in and solve for $\cos\theta$. Because $\theta$ is acute (between 0° and 90°), cosine is positive, so you'll take the positive square root—no ambiguity needed.

The key here is the Pythagorean identity $\sin^2\theta + \cos^2\theta = 1$, which connects sine and cosine for any angle. Since you know $\sin\theta$, you can substitute it in and solve for $\cos\theta$. Because $\theta$ is acute (between 0° and 90°), cosine is positive, so you'll take the positive square root—no ambiguity needed.