Algebra and Trigonometry 2e

# Key Terms

### Key Terms

amplitude
the vertical height of a function; the constant $A A$ appearing in the definition of a sinusoidal function
arccosine
another name for the inverse cosine; $arccosx= cos −1 x arccosx= cos −1 x$
arcsine
another name for the inverse sine; $arcsinx= sin −1 x arcsinx= sin −1 x$
arctangent
another name for the inverse tangent; $arctanx= tan −1 x arctanx= tan −1 x$
inverse cosine function
the function $cos −1 x, cos −1 x,$ which is the inverse of the cosine function and the angle that has a cosine equal to a given number
inverse sine function
the function $sin −1 x, sin −1 x,$ which is the inverse of the sine function and the angle that has a sine equal to a given number
inverse tangent function
the function $tan −1 x, tan −1 x,$ which is the inverse of the tangent function and the angle that has a tangent equal to a given number
midline
the horizontal line $y=D, y=D,$ where $D D$ appears in the general form of a sinusoidal function
periodic function
a function $f( x ) f( x )$ that satisfies $f( x+P )=f( x ) f( x+P )=f( x )$ for a specific constant $P P$ and any value of $x x$
phase shift
the horizontal displacement of the basic sine or cosine function; the constant $C B C B$
sinusoidal function
any function that can be expressed in the form $f( x )=Asin( Bx−C )+D f( x )=Asin( Bx−C )+D$ or $f( x )=Acos( Bx−C )+D f( x )=Acos( Bx−C )+D$