Home > maths > Sec, Cosec, Cot

Sec, Cosec, Cot

Sec, cosec and cot are all functions in trigonometry. They are simply equal to one over on of the other functions, ie cos, sin and tan.


Sec = 1/cos

Cosec = 1/sin

cot = 1/tan

You can remember which is paired with which using the third letter rule. This is that the third letter is the first letter of the corresponding function ie)

sec goes with cos
cosec goes with sin
cot goes with tan

  1. Assistance
    May 12, 2009 at 2:04 am

    If Tan=sin/cos, then whats Sin=?, and Cos?

    • May 12, 2009 at 3:18 pm

      Tan, sin and cos are to do with the ratios of the sides of right angled triangles with a given angle in one of the corners.
      Tan = sin/cos can derived from these ratios, or these ratios can be derived from defining tan as sin/cos.
      In answer to your question,
      sin = opposite/hypotenuse
      cos = adjacent over hypotenuse
      where the hypotenuse is the longest side of the right angled triangle, the adjacent is the side next to the one your taking the angle from and opposite is the remaining side, which is opposite the angle.

      I have other posts on trigonometry which explain this in more detail which you should be able to find using the search feature on the right hand side of the page.

      hope this helped,

  1. No trackbacks yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: