Basics Trig Flashcards
What is the definition of a right triangle?
A triangle that has one angle measuring 90 degrees.
What are the three sides of a right triangle called?
Opposite, adjacent, and hypotenuse.
True or False: The hypotenuse is always the longest side in a right triangle.
True.
What is the Pythagorean theorem formula?
a² + b² = c², where c is the hypotenuse.
Fill in the blank: The sine of an angle is the ratio of the length of the _____ side to the length of the hypotenuse.
opposite
What is the cosine of an angle?
The ratio of the length of the adjacent side to the length of the hypotenuse.
What is the tangent of an angle?
The ratio of the length of the opposite side to the length of the adjacent side.
True or False: The sine, cosine, and tangent functions are defined only for right triangles.
False; they can be extended to all angles using the unit circle.
What is the range of the sine function?
From -1 to 1.
What is the range of the cosine function?
From -1 to 1.
What is the range of the tangent function?
From -∞ to +∞.
Fill in the blank: The angle whose sine, cosine, or tangent value is given is called the _____ angle.
reference
What is the unit circle?
A circle with a radius of 1 centered at the origin of a coordinate plane.
True or False: The coordinates of a point on the unit circle can be used to find sine and cosine values.
True.
What is the sine of 0 degrees?
0.
What is the cosine of 90 degrees?
0.
What is the tangent of 45 degrees?
1.
Fill in the blank: The reciprocal of sine is called _____.
cosecant
Fill in the blank: The reciprocal of cosine is called _____.
secant
Fill in the blank: The reciprocal of tangent is called _____.
cotangent
What is an angle measured in radians?
An angle measured based on the radius of a circle; 180 degrees equals π radians.
