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Right-Triangle Trigonometry flashcards
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- Choose a ratio to recover a sideSine, Cosine, and Tangent
- Choose the ratio that connects the two sides you actually have.
- When should I use sine and cosine?Sine, Cosine, and Tangent
- Identify the correct side ratio for an acute right-triangle angle.
- What method supports choose a ratio to recover a side?Sine, Cosine, and Tangent
- opposite=hypotenuse·sin θ
- TangentSine, Cosine, and Tangent
- Tangent compares the legs directly.
- Sine and cosineSine, Cosine, and Tangent
- Sine uses the far leg; cosine uses the near leg.
- What must I check in sine, cosine, and tangent?Sine, Cosine, and Tangent
- Define opposite and adjacent relative to the selected acute angle; the hypotenuse is always opposite 90°
- What method supports tangent?Sine, Cosine, and Tangent
- tan θ=opposite/adjacent
- What method supports sine and cosine?Sine, Cosine, and Tangent
- sin θ=opposite/hypotenuse; cos θ=adjacent/hypotenuse
- When should I use choose a ratio to recover a side?Sine, Cosine, and Tangent
- Select sine, cosine, or tangent using the known and requested sides.
- When should I use tangent?Sine, Cosine, and Tangent
- Use the ratio of the two legs.
- Angle recovery and modeFinding Missing Sides and Angles
- Inverse trig asks which angle has that ratio.
- When should I use missing leg from an exact angle?Finding Missing Sides and Angles
- Use an exact trigonometric ratio to find a side.
- What method supports angle recovery and mode?Finding Missing Sides and Angles
- θ=arctan(opposite/adjacent), 0°<θ<90°
- Missing hypotenuseFinding Missing Sides and Angles
- The longest side must be larger, so divide by the leg fraction.
- Missing leg from an exact angleFinding Missing Sides and Angles
- An exact angle can give an exact side multiplier.
- What must I check in finding missing sides and angles?Finding Missing Sides and Angles
- Use degree mode for degree angles and radian mode for radian angles; inverse-trig angle recovery is a supporting extension
- What method supports missing hypotenuse?Finding Missing Sides and Angles
- hypotenuse=adjacent/cos θ
- What method supports missing leg from an exact angle?Finding Missing Sides and Angles
- sin30°=1/2; cos60°=1/2
- When should I use angle recovery and mode?Finding Missing Sides and Angles
- Use an inverse function or a standard exact ratio to find an angle.
- When should I use missing hypotenuse?Finding Missing Sides and Angles
- Divide by the known side-to-hypotenuse ratio.
- Recover a complementary ratioComplementary Angles and Trigonometric Relationships
- Use the complementary relationship before reaching for an inverse calculator.
- When should I use complementary acute angles?Complementary Angles and Trigonometric Relationships
- Recover the other acute angle in a right triangle.
- What method supports recover a complementary ratio?Complementary Angles and Trigonometric Relationships
- sin²θ+cos²θ=1; cosβ=sinα when α+β=90°
- Cofunction ratiosComplementary Angles and Trigonometric Relationships
- Sine of one corner is cosine of the other.
- Complementary acute anglesComplementary Angles and Trigonometric Relationships
- The two sharp corners split a right angle.
- What must I check in complementary angles and trigonometric relationships?Complementary Angles and Trigonometric Relationships
- The cofunction identities pair angles summing to 90°; do not confuse them with equal-angle claims
- What method supports cofunction ratios?Complementary Angles and Trigonometric Relationships
- sin θ=cos(90°−θ)
- What method supports complementary acute angles?Complementary Angles and Trigonometric Relationships
- α+β=90°
- When should I use recover a complementary ratio?Complementary Angles and Trigonometric Relationships
- Translate a known ratio to the complementary angle.
- When should I use cofunction ratios?Complementary Angles and Trigonometric Relationships
- Use a sine-cosine complement identity.
- Quadrants and reference anglesDegrees, Radians, and Relevant Unit-Circle Relationships
- Find the reference angle and then apply the quadrant signs.
- When should I use degree-radian conversion?Degrees, Radians, and Relevant Unit-Circle Relationships
- Convert angle measures with π radians equal to 180°.
- What method supports quadrants and reference angles?Degrees, Radians, and Relevant Unit-Circle Relationships
- cos(180°−α)=−cosα; sin(180°−α)=sinα
- Unit-circle coordinatesDegrees, Radians, and Relevant Unit-Circle Relationships
- Cosine is left-right; sine is up-down.
- Degree-radian conversionDegrees, Radians, and Relevant Unit-Circle Relationships
- Use 180° and π radians as equal measures.
- What must I check in degrees, radians, and relevant unit-circle relationships?Degrees, Radians, and Relevant Unit-Circle Relationships
- A full revolution is 2π radians or 360°; unit-circle coordinates are (cosθ,sinθ) and quadrant signs matter
- What method supports unit-circle coordinates?Degrees, Radians, and Relevant Unit-Circle Relationships
- (x,y)=(cosθ,sinθ), x²+y²=1
- What method supports degree-radian conversion?Degrees, Radians, and Relevant Unit-Circle Relationships
- radians=degrees·π/180
- When should I use quadrants and reference angles?Degrees, Radians, and Relevant Unit-Circle Relationships
- Use a reference angle and signs to find an exact trig value.
- When should I use unit-circle coordinates?Degrees, Radians, and Relevant Unit-Circle Relationships
- Connect sine and cosine to horizontal and vertical coordinates.
- Sloped path and vertical riseTrigonometric Word Problems
- A sloped length is the longest side, so choose sine for the rise.
- When should I use angle of elevation?Trigonometric Word Problems
- Relate vertical rise and horizontal distance with tangent.
- What method supports sloped path and vertical rise?Trigonometric Word Problems
- vertical rise=sloped length·sinθ
- Observer heightTrigonometric Word Problems
- The trig triangle starts at eye level, so add that level back.
- Angle of elevationTrigonometric Word Problems
- Elevation connects height above the sightline to horizontal distance.
- What must I check in trigonometric word problems?Trigonometric Word Problems
- Assume level ground and vertical objects only when stated; add observer height separately from the triangle’s vertical rise
- What method supports observer height?Trigonometric Word Problems
- object height=instrument height+d·tanθ
- What method supports angle of elevation?Trigonometric Word Problems
- rise=horizontal distance·tanθ
- When should I use sloped path and vertical rise?Trigonometric Word Problems
- Use sine when the known distance is a hypotenuse.
- When should I use observer height?Trigonometric Word Problems
- Add instrument height after finding the vertical rise.
