1. The problem is to find the angle $A$ given that $\cos A = \frac{17}{23}$.\n\n2. The formula used is $A = \arccos\left(\frac{17}{23}\right)$, where $\arccos$ is the inverse cosine function that returns the angle whose cosine is the given value.\n\n3. To solve this on a calculator, follow these steps:\n - Make sure your calculator is set to degree mode if you want the answer in degrees.\n - Enter the value $17 \div 23$ to get the decimal equivalent.\n - Use the $\arccos$ or $\cos^{-1}$ function on your calculator and input the decimal value.\n\n4. The calculator will output the angle $A$ in degrees, which is approximately $42.34^\circ$.\n\nThis means the angle $A$ whose cosine is $\frac{17}{23}$ is about $42.34$ degrees.