How do you evaluate sec(pi)?

We have to calculate sec pi

Solution

We know that pi = 180 degrees

we can express sec in terms of cos as

sec x = 1/cos x

sec 180 = 1 / cos (180)

We have learnt that cos 180 = -1

sec 180 = 1 / (-1)

sec 180 = -1

Answer

sec pi = -1