All Students Take Calculus (ASTC) is a mnemonic in math that is used to help people memorize the sign values of the trigonometric functions in the 2 dimensional Cartesian coordinate system. The letters ASTC signify the order of the trigonometric functions to which of the functions are positive, starting in the top right quadrant, and moving counter clockwise.

The first, top-right quadrant, A for All, all trigonometric functions are positive in this quadrant.
The second, top-left quadrant, S for Sine, sine functions are positive in this quadrant.
The third, bottom-left quadrant, T for Tangent, tangent functions are positive in this quadrant.
The fourth, bottom-right quadrant, C for Cosine, cosine functions are positive in this quadrant. Not to be confused with pneumonic. ... Fig. ... In mathematics, the trigonometric functions are functions of an angle, important when studying triangles and modeling periodic phenomena. ...

External links

• Mnemonics Collection for Students - In spite of your efforts to organize your information, you may still find that you have a big list of stuff to remember..
• Mnemonic-device.eu - A growing collection of assistive mnemonics.
• Mnemonic Dictionary - Word Power Made Easy using Mnemonics approach.