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Saturday, February 22, 2014

ID #1: Unit N Concept 7: Knowing all Degrees and Radians Around the Unit Circle, Knowing all the Ordered Pairs Around the Unit Circle, Understanding and Applying ASTC to the Unit Circle

INQUIRY ACTIVITY SUMMARY



Many parts of this triangle have a specific label based on the Special Right Triangles rule. The first rule includes that the hypotenuse must equal 1 (ALWAYS). According to the 30, 60, 90 angles rules, the adjacent side to 30 (the side labeled x) has the value of x radical 3; the opposite side from the 30 degree angle (the side labeled y) has the value of 1/2; the hypotenuse of a 30 degree angle (the side labeled r) has the value of 2x . If this triangle were to be put in the unit circle across in the x- axis the origin (0,0) would be (radical 3/ 2, 0), and right above the previous point would be (radical 3/2, 1/2).



Along with the previous triangle, may rules apply to the sides and angles of the 45 degree triangle. The same rule about the hypotenuse applies to this triangle that it must equal 1 (labeled r) with the value of x radical 2. The adjacent side (labeled x) has the value of radical 2/2. the side opposite (labeled x) was valued the same of radical 2/2. The values are found when equaling the x's to the hypotenuse (x radical 2) leaving both of the sides equaling radical 2/2. If this triangle was inserted onto the unit circle, across from the origin (0,0) would lie the point (radical 2/2, 0), and above the previous point would be the point (radical 2/2, radical 2/2).



Just as the previous triangles, this 60 degree triangle includes rules to its sides and angles. The rule about the hypotenuse (labeled r) applies to this triangle with the value of 2x (the same as the 30 degree triangle). The side adjacent to the hypotenuse (labeled x) has the value of 1/2, and opposite from that side (labeled y) is valued radical 3/2. If this triangle were to be placed into the unit circle, across from the origin (0,0) on the x-axis would be point (1/2, 0), and right above would be point (1/2, radical 3/ 2).

                                                                                                               
All depending on where the ASTC is found on the circle, we will know which sin, cos, or cot is positive or negative. The ASTC starts from up right to the bottom from the left. Quadrant A (I) has ALL positive and NONE negative. Quadrant S (II), has csc/sin positive, and sec/cos, tan/cot negative. In quadrant T (III) tan/cot is positive, and csc/sin, cos/sec negative. Finally quadrant C (IV) has cos/sec positive and csc/sin, tan/cot negative. 


  1. The coolest thing I learned from this activity was realizing that all along there were triangle involved that made the unit circle easier to understand. 
  2. This activity will help me in this unit because it allowed me to find what i need to find using prior knowledge instead of just memorizing the entire unit circle. 
  3. Something I never realized before about special right triangles and the unit circle is that they are connected through the point and radians values.


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