# How to remember the Unit Circle

### Common Core Standard F.TF.2 High School Geometry

### Use this Math trick as an easy way to remember the unit circle

Your

**hand**can be used as a reference to help remember the**unit circle**.The

**tips**of your fingers remind you that will be taking the**square root**of the numerator, and your**palm**reminds you that the denominator will equal**two**.See

**Figure 1.**for what each part of hand will represent.Your

**pinkie**represents**0**degrees, your**ring**finger equals**30**degrees, the**middle**finger equals**45**, and your**pointing**finger equals**60**degrees on the**Unit Circle**.**Cosine**is written first, followed by

**Sine**

## This is part two of " Easy Way to Remember Unit Circle" The video shows you how to go from Quadrant one to the complete unit Circle

## How do you remember the sign values for the four quadrants of the unit circle?

One easy method is to think of each

**Quadrant**in terms of the x and y axis.If you are graphing on a coordinate plane you know all values to the

**right**of the**y axis**are positive, and values to the**left**are**negative.**In the same way everything

**above**the**x axis**has a positive value, and items below the**x axis**have a**negative value**.Look at

**Quadrant 1**, all items in this**quadrant**are right of the y axis, and above the x axis. Therefore, the sign values for this Quadrant are (+, +).**Remember the x value is always written before the y value.**

Look at

**Quadrant 2**, all sign values in this Quadrant are left of the y axis, and above the x axis.Therefore the values for x are negative, and positive for y values so you write the values (-,+).

**Quadrant 3**has sign values (-,-) and

**Quadrant 4**has sign values (+,-).

**The unit circle has a radius of one.** The position (1, 0) is where x has a value of 1, and y has a value of 0. This starting position in the unit circle represents 0 degrees.

The position (0,1) represents 90 degrees.

The position (-1,0) represents 180 degrees.

The position (0, -1) represents 270 degrees.

A full circle is 360 degrees and ends at the starting position (0, 1)

You can remember the

**values by remembering***trig function***All**

**Students**

**Take**

**Calculus**

**A = All positive**

**S= Sine and it’s reciprocal cosecant are positive**

**T = Tangent and it’s reciprocal cotangent are positive**

**C = Cosine and it’s reciprocal secant are positive**