Section 6.1.2
Inverse Sine and Cosine
Lesson Objective:
Students will:
• Graph the relations for inverse sine and
cosine.
1
1
y

sin
x
and
y

cos
x
• Restrict the range for
to make them functions.
• Use inverse functions to solve for angles
which are not special angles in the unit
circle.
Definition
•The inverse of sin x is arcsin x or sin-1x
•The notation y=arcsin x can be thought of
as “the arc whose sine is …” This connects
the inverse back to the unit circle
•The inverse of cos x is arccos x or cos-1x
Important Idea
Trig
Function
Inverse Trig Function
y  sin x x  sin y or x  arcsin y
1
y  cos x x  cos y or x  arccos y
1
Closure
After using the unit circle or calculator to find one angle
for the inverse of a function, how can you easily find the
additional angle?
Assignment
Pg 276 #6-26 to 6-34