Question

Find the exact value of tan-1(1).
pi/4
7pi/4
5pi/4
3pi/4

Answer 1

@RadEn

Answer 2

it like tanθ = 1 then find θ
what the measure of θ when the value of tanθ = 1 ?

Answer 3

here θ is the special degrees, you have to memorize it

Answer 4

this link might helps to memorize all value trigono in the special angles
http://2000clicks.com/mathhelp/GeometryTrigEquivIdentities00.aspx

Answer 5

@jim_thompson5910

Answer 6

dont understand it

Answer 7

oh so it would be pi/4? @RadEn

Answer 8

there is a table in that link, you can see the answer :)
yeah, one of the answer is pi/4, the other is ... (see the table again)

Answer 9

I can only have one option?

Answer 10

no, i saw there are 2 options be right answer

Answer 11

oh but i can only pick one... so im confused

Answer 12

ill go with pi/4

Answer 13

if it is in the 1st quadrant, yeah you are right it is pi/4
but if it is in the 3rd quadrant so the answer is 5pi/4.
is there other information which quadrant for the θ ? if there is no information so there are 2 options be right answer i think