Find Sine Given a Point in Coordinate System

Find Sine Given a Point in Coordinate System
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2014-05-13 21:00
In collections CCGPS AA Unit 5 Lesson 1
This example demonstrates how to find the sine value given a point in a coordinate system by constructing a right triangle. Key math concepts include the sine function in trigonometry. Construction highlights include using GeoGebra commands for circle, segment, angle, and other objects.

GeoGebra Commands & Parameters

  1. LaTeX(steps) → counter
  2. Circle(B, A) → c
  3. LaTeX("\text{Make a sketch.}") → text1
  4. Segment(B, A) → hypotenuse
  5. Segment(B, C) → Adjacent
  6. Segment(C, A) → opposite
  7. Angle(A, B, C) → θ_1
  8. If((0 ≤ x(A)) ∧ (0 ≤ y(A)), LaTeX["\text{I}"], If[(0 > x(A)) ∧ (0 ≤ y(A)), LaTeX["\text{II}"], If[(0 > x(A)) ∧ (0 > y(A)), LaTeX["\text{III}"], LaTeX["\text{IV}"]]]) → quadrant
  9. LaTeX("\text{Pythagorean Theorem}") → text12
  10. LaTeX("\text{Square and add.}") → text16
  11. LaTeX("\text{Sine ratio}") → text22
  12. Angle((radius, 0), B, A) → θ
  13. If((0 ≤ x(A)) ∧ (0 ≤ y(A)), LaTeX["\text{A: all positive so sine is positive}"], If[(0 > x(A)) ∧ (0 ≤ y(A)), LaTeX["\text{S: sine and cosecant are positive}"], If[(0 > x(A)) ∧ (0 > y(A)), LaTeX["\text{T: tangent and cotangent are positive; sine is negative}"], LaTeX["\text{C: cosine and secant are positive sine is negative}"]]]) → signsASTC
  14. If((0 ≤ x(A)) ∧ (0 ≤ y(A)), LaTeX["\text{y-coordinate is positive so sine is positive}"], If[(0 > x(A)) ∧ (0 ≤ y(A)), LaTeX["\text{y-coordinate is positive so sine is positive}"], If[(0 > x(A)) ∧ (0 > y(A)), LaTeX["\text{y-coordinate is negative so sine is negative}"], LaTeX["\text{y-coordinate is negative so sine is negative}"]]]) → signsCoords
  15. If(y(A) ≥ 0, "", "-") → signPick
  16. LaTeX("\text{Move the slider to solve the problem.}") → text0
  17. LaTeX("\text{Sketch the triangle, the angle, and the reference angle.}") → text3
  18. LaTeX("\text{The reference angle is the angle the terminal side makes with the x-axis.}") → text4
  19. LaTeX("\text{Sine is the ratio of the length of the opposite side to the length of the hypotenuse; }\cr\text{therefore, these two lengths must be determined.}") → text8
  20. LaTeX("\text{Use the buttons below to return to the original problem or}\cr\text{randomly generate a similar practice problem.}") → text32
  21. LaTeX((("\text{point: }\textcolor{#000099}{" * A) * "}")) → Problem
  22. LaTeX((("\text{Plot }\textcolor{#000099}{" * A) * "} \text{ on a coordinate plane and draw the terminal side extending from }\cr\text{the origin through that point.}")) → text2
  23. LaTeX((("\text{The length of the opposite side is the magnitude of the y-coordinate, }\textcolor{#CC0000}{" * abs(y(A))) * ".}")) → text9
  24. LaTeX((("\text{The length of the adjacent side is the magnitude of the x-coordinate, }\textcolor{#006633}{" * abs(x(A))) * ".}")) → text11
  25. LaTeX("c^2=a^2+b^2") → text13
  26. LaTeX((("c=\sqrt{" * csq) * "}")) → text19
  27. LaTeX((((("\text{Substitute }" * abs(y(A))) * " \text{ for the opposite side }\cr\text{and }\sqrt{") * csq) * "} \text{ for the hypotenuse.}")) → text24
  28. LaTeX((("\text{The sign of sine is given by the sign of the y-coordinate. }\cr\text{The }" * signsCoords) * ".")) → text29
  29. LaTeX((("\text{The sketch shows that reference angle is in Quadrant }" * quadrant) * ".")) → text5
  30. LaTeX("\text{Use the sine of the reference angle to determine the sine of the angle }\textcolor{#CC9900}{θ}.") → text26
  31. LaTeX("\text{Determine the sign of }\sin(\textcolor{#CC9900}{θ}) \text{ by recalling the ASTC pattern or by considering }\cr\text{the signs of the x- and y-coordinates.}") → text27
  32. LaTeX((((((("\sin(\textcolor{#CC9900}{\theta})=" * signPick) * "\frac{") * abs(y(A))) * "}{\sqrt{") * csq) * "}}")) → text30
  33. LaTeX((((((((("\text{For a positive angle }\textcolor{#CC9900}{θ} \text{ in standard position with a terminal side that passes}\cr\text{through the point }" * A) * "\text{, }sin(\textcolor{#CC9900}{θ})=") * signPick) * "\frac{") * abs(y(A))) * "}{\sqrt{") * csq) * "}.}")) → text31
  34. LaTeX("\text{The magnitude of the x-coordinate is the length of the adjacent side and the }\cr\text{magnitude of the y-coordinate is the length of the opposite side.}\cr\text{The hypotenuse can be found using the Pythagorean Theorem.}") → text6
  35. LaTeX("\text{In order to find the length of the hypotenuse, find the length of the adjacent side.}") → text10
  36. LaTeX((((("c^2 = (" * abs(y(A))) * ")^2 + (") * abs(x(A))) * ")^2")) → text15
  37. LaTeX((((((("c^2 = " * bsq) * " + ") * asq) * "=") * csq) * "")) → text17
  38. LaTeX((((("\text{Substitute }\textcolor{#CC0000}{" * abs(y(A))) * "} \text{ for a and }\textcolor{#006633}{") * abs(x(A))) * "}\text{ for b.}")) → text14
  39. LaTeX("\text{Take the square root of both sides.}") → text18
  40. LaTeX("\text{Find the sine of the reference angle}.") → text20
  41. LaTeX("\text{Now that the lengths of the opposite side and the hypotenuse are known, }\cr\text{substitute these values into the sine ratio}.") → text21
  42. LaTeX("sine=\frac{\text{length of opposite side}}{\text{length of hypotenuse}}") → text23
  43. LaTeX((((("sine=\frac{" * abs(y(A))) * "}{\sqrt{") * csq) * "}}")) → text25
  44. LaTeX((((("\text{The terminal side is in Quadrant }" * quadrant) * " \text{. According to ASTC,}\cr") * signsASTC) * ".")) → text28
  45. LaTeX("\text{Determine the sign of }\sin(\theta) \text{ by recalling the ASTC pattern or by considering }\cr\text{the signs of the x- and y-coordinates.}") → text7

AI Drawing Prompt Reference

Draw a point A in the coordinate system and draw the terminal side from the origin through point A to form a right triangle with point A as the right angle vertex and the origin as the other right angle vertex. Construct an angle θ with point A as the vertex and find its reference angle. Use the Pythagorean theorem to calculate the hypotenuse length, then determine the sine value based on the lengths of the opposite side and the hypotenuse. Pay attention to the signs of point A's coordinates to determine the sign of the sine value.
The prompt above was compiled from the original drawing commands and is for reference only.