Use your knowledge of UC to find the values of
Section 7-6 The Inverse Trigonometric Functions Objective: To find values of the inverse trigonometric functions.
Reminder about reference angles
REVIEW CONCEPTS:
review One to one function Restricted domain Inverse functions –Inverse function equations algebraically. –Inverse functions graphically.
Trig FUNCTIONS Sine, cosine and tangent are all functions. Are they all one-to-one functions?
Notice how the axes are scaled!
Trig functions Does tan θ have an inverse that is a function? Justify your answer. If you answered no, you are right. However, we need to have a way to “undo” tan θ.
The graph does not have an inverse function.
Inverse of trig functions Restrict domain to f(x)=Tan x Inverse function is Tan -1 x Notice T is capitalized
Tan x has an inverse. Notice how the axes are scaled!
Sec 7.6 Warm Up Day 2
Notice how the axes are scaled!
Inverse of trig functions
Notice how the axes are scaled!
Inverse of trig functions Restrict domain to 0 <x < F(x)=Cos x Inverse function is Cos -1 x
Notice how the axes are scaled!
graphs of trig functions graph of inverse funtions
Restricted domains summarized: Notice the restricted domain for each of the inverse functions includes the first quadrant… i.e. the reference angle.
Sine Function: sin(30°) = 0.5 Inverse Sine: Sin -1 (0.5) = 30°
tan(angle value)= ratio Tan -1 (ratio)= angle value sin(angle value)= ratio Sin -1 (ratio)= angle value cos(angle value)= ratio Cos -1 (ratio)= angle value
Example 1 Find Tan -1 2 with a calculator. 0<θ<360° First make sure your calculator is in the correct mode.
Example 2 Find Tan -1 (-1) without a calculator. 0<θ<2
Restricted domains summarized:
Use your knowledge UC and RA:
Warm UP Day 2: :
Parent graph: sine function
review graphing: Study the graphs below. Draw inverse of each graph.
Example 3 A.) Find Sin -1 (-0.8) with a calculator. 0<θ<360° B.) Find Cos -1 (-0.5) without a calculator. 0<θ<2
Example 4 Hint: pay attention to restricted domain. A) Find the value of the above expression without a calculator.
Example 4 Hint: pay attention to restricted domain. B) Find the value of with a calculator.
No matter the mode setting is…
Homework Sec 7.6 written exercises Day 1: #1-9 All, read #10 Day 2: #11-21 All
Review ction_5_1.html