Question

Pre calculus: Inverse functions (Question in reply)

Answer 1

\[\sec ^-1 (1)\]

Answer 2

An angle whose secant is 1.
An angle whose cosine is 1/1 = 1.
Name it!

Answer 3

180 degrees?

Answer 4

\(\bf sec^{-1}(1)\implies sec(\theta)=1\implies \cfrac{1}{cos(\theta)}=1\implies \cfrac{1}{1}=cos(\theta)
\\ \quad \\
\implies cos^{-1}\left(\cfrac{1}{1}\right)=cos^{-1}[cos(\theta)]\implies cos^{-1}(1)=\theta\)

Answer 5

check your Unit Circle for it

Answer 6

For what exactly?

Answer 7

for the angle WHOSE COSINE is 1

Answer 8

pie. correct? or, 180 degrees to be specific.

Answer 9

is that what you've got from the Unit Circle?

Answer 10

http://www.mathsisfun.com/geometry/images/circle-unit-radians.gif <---

Answer 11

yeah, thinking about a unit circle, it should actually be 0 degrees, correct? Else 180 would have been -1.

Answer 12

yeap, 180 would be -1
0 or \(2\pi\) are 1

Answer 13

Then I thank thee kind sir. You have been most helpful.

Answer 14

yw