# Trig problems

lionely
tan 2θ= -1

I don't understand how to work this question could someone walk me through it?

ranging between -180 and 180

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Homework Helper
For what value of x does $\tan(x)=-1$ ?

lionely
I believe -45

skiller
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Staff Emeritus
Homework Helper
I believe -45

Is that the only value??

lionely
Yes what are the possible values of theta and I'm sure, I haven't started working in radians at school as yet... =/

Homework Helper
Yes what are the possible values of theta and I'm sure, I haven't started working in radians at school as yet... =/

Ok so you know that there are infinitely many solutions to tan(x)=-1 right? Because just like how the sin and cos graphs go on forever, the tan function does as well. Anyway, are you expected to find all the solution for θ between -180o and 180o?

And another thing, if tan(-45o)=-1 and we have that 2θ=-45o then what is θ?

lionely
Theta would be -22.5 oh and I forgot to mention the question asked between -180 and 180 sorry.