# Video: Calculating the Cosine Function of a Given Angle

Calculate cos 80° 36′ 36″ giving the answer to four decimal places.

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### Video Transcript

Calculate cos of 80 degrees, 36 minutes, and 36 seconds, giving the answer to four decimal places.

Before we start this question, we need to know that one degree is equal to 60 minutes. And one degree is also equal to 3600 seconds as there are 60 seconds in a minute. To work out how many degrees there are in 36 minutes, we divide 36 by 60. This gives us 0.6 degrees. To calculate how many degrees there are in 36 seconds, we need to divide 36 by 3600. This gives us 0.01 degrees.

Putting these answers together gives us that 36 minutes and 36 seconds is equal to 0.61 degrees. This means that calculating cos of 80 degrees, 36 minutes, and 36 seconds is the same as calculating cos of 80.61 degrees. Typing this into our calculator gives us an answer of 0.1632.

Therefore, cos of 80 degrees, 36 minutes, and 36 seconds to four decimal places is 0.1632. We can use this to solve any problem, where the angle is given in minutes and seconds by first converting it into degrees.