Inverse Tangent FunctionsLesson 5.6

Remember… y = tan x

y = tan-1 x• If we took y = tan x on its entire

domain, the inverse would not be a function

• So, we restrict the domain of tan-1x to –π/2 ≤ y ≤ π/2

Different calculators tan-1 x = arctan= atan

Remember… y = tan x

• Lorem

y = tan-1 x

• Lorem

Example 1• Evaluate Arctan 30 to the nearest

thousandth of a degree.

tan x = 30

x = 88.09˚

Example 2• Evaluate tan-1 in radians

tan x =

x = arctan

x = 30˚ so π/6

3

3

3

3

3

3

Example 3• Give the angle θ the line y = mx

makes with the positive part of the x – axis as a function of the slope of the line.

θ

m

1

Tan θ = m

θ = atan m

Homework

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