PreCal nakamamatay

• What does the word "trigonometry" derive from?

  Greek words for trigonon and metron
• What does trigonometry study?

  Relationships between triangle sides and angles
• What forms an angle?

  Two lines or rays intersecting
• What is the vertex of an angle?

  The common point where rays intersect
• How is the initial side of an angle determined?

  By one ray or line
• What does the terminal side of an angle determine?

  The amount of rotation from the initial side
• How much of a complete revolution does a 1 degree angle represent?

  $\frac{1}{360}$ of a complete revolution
• What is the unit circle?

  A circle with radius one at the origin
• What are the two basic units of angle measures?

  Degrees and Radians
• What does each terminal side correspond to in the unit circle?

  The hypotenuse of a right triangle
• What is the formula for radian measure?

  $\Theta \text{ (in radians)} =$$\frac{s}{r}$
• What does 's' represent in the radian measure formula?

  Length of the subtended arc
• What does 'r' represent in the radian measure formula?

  Length of the radius
• How do you convert degrees to radians?

  Multiply by $\frac{\pi}{180°}$
• How do you convert radians to degrees?

  Multiply by $\frac{180°}{\pi}$
• What defines an angle in standard position?

  Vertex at the origin, initial side on x-axis
• What indicates a positive angle measurement?

  Counterclockwise rotation
• What are coterminal angles?

  Angles with the same terminal side
• How do you find coterminal angles in degrees?

  Add or subtract 360°
• How do you find coterminal angles in radians?

  Add or subtract $2\pi$
• What are circular functions also known as?

  Trigonometric functions
• What do circular functions relate to?

  Relationship of sides in a triangle
• What is the sine function in terms of the unit circle?

  $\sin \Theta =$$y$
• What is the cosine function in terms of the unit circle?

  $\cos \Theta =$$x$
• What is the tangent function in terms of the unit circle?

  $\tan \Theta =$$\frac{y}{x}$
• What is a reference angle?

  Least positive acute angle with x-axis
• How does a reference angle help in trigonometry?

  Finds exact value of circular functions
• What are the signs of circular functions in each quadrant?

  • I: All positive
  • II: Sin and csc positive
  • III: Tan and cot positive
  • IV: Cos and sec positive
• What is amplitude in trigonometric functions?

  Height of a function or curve
• How is amplitude defined in terms of function values?

  Half the difference between min and max values
• What is the period of a function?

  Length of a cycle of a function
• What is the formula for the period of a function?

  $\text{Period} =$$\frac{2\pi}{|B|}$
• What is phase shift in trigonometric functions?

  Amount of horizontal wave shift
• What is vertical shift in trigonometric functions?

  Amount of vertical wave shift
• What is the general form of a sine function?

  $y =$$A \sin(Bx - C) +$$D$
• What is an identity in mathematics?

  An equation true for any variable value
• What is a conditional equation?

  An equation satisfied by specific values
• What is the reciprocal identity for sine?

  $\sin x =$$\frac{1}{\csc x}$
• What is the reciprocal identity for cosine?

  $\cos x =$$\frac{1}{\sec x}$
• What is the reciprocal identity for tangent?

  $\tan x =$$\frac{1}{\cot x}$