Final answer:
To calculate cos⁻¹(-0.25713), ensure the calculator is in degree mode and enter the value into the inverse cosine function, which will yield an answer within the range of 90 to 180 degrees.
Step-by-step explanation:
To find the approximate value of cos⁻¹(-0.25713) correct to five decimal places using a calculator, you should first check that your calculator is set to degree mode if you want the answer in degrees. Once that's set, you can input the value inside the inverse cosine function (usually labeled as cos⁻¹, acos, or sometimes you might need to use a shift or second function key to access it). After entering the value -0.25713, your calculator will provide the result. It's important to remember that the range of the inverse cosine function is from 0 to 180 degrees or from 0 to π radians, depending on your calculator setting. So the answer will be an angle within this range. Since it is a negative cosine value, the angle will be between 90 and 180 degrees.