Question

solve: 2tanθ+5=0

Answer 1

Start with isolating \(\large \rm \tan \theta\). Can you do so?

Answer 2

subtract 5 and then divide by 2

Answer 3

Yes, so what do you get?

Answer 4

-5/2

Answer 5

And do you think that \(\rm tan\theta\) ever is -5/2?

Answer 6

uhm... thats where im stuck but i guess not ?

Answer 7

Yes, it actually is. :p

Answer 8

It is :P .

Answer 9

haha whoops

Answer 10

I was just playing, but do you know how to solve the rest?

Answer 11

no i need help :/

Answer 12

like i dont know what quadrant it would lie on or what degree it would be

Answer 13

Well what's the period of Tan ?

Answer 14

180

Answer 15

Remember than has periodic solutions.

Answer 16

You know how to use the unit circle?

Answer 17

tan*

Answer 18

yes

Answer 19

Wait never mind. I have no idea how to do this :( .

Answer 20

aww haha

Answer 21

lol, actually just use your calculator to calculate.\[\large \rm {\tan ^{-1}(\tan \theta)} = \tan^{-1}\left(-{5 \over 2}\right)\]\[\rm \large \theta = \tan^{-1}\left(-{5 \over 2} \right)\]

Answer 22

lol thats actually what i did. i just need to find two values of θ that satisfy

Answer 23

Hint: Use that the period of tan is \(\rm \pi\).

Answer 24

so it would be -68 degrees right ?

Answer 25

So find one solution and then add pi to it.

Answer 26

why add pi?

Answer 27

Ohh then I was right... Felt too simple so I figured it must be different.

Answer 28

Because the period of tangent is pi!

Answer 29

Yeah, -68.2

Answer 30

oh right ..sorry

Answer 31

And add pi to it a.k.a 180 degrees.

Answer 32

i think i got it ...thank you

Answer 33

You're welcome. Hehe :)