Find the exact value of the tangent of 15 degrees

Use trig identities to find the exact value.

[CandyInTheClouds]

Where does the tan 4pi/12 and 3pi/12 come from? It might have helped to use the unit circle and draw a pic.

I've been using tan (45 - 30) but always get hung up factoring everything out when radicals are thrown in there. This looks easier, but where do those pi values come from?


Could you try to be more explicit with your explanations? A lot of times when people do this tutorials they kind of brush over key elements, but if someone is going far enough to look at these things, they probably need very detailed directions.

[mathematicssolved]

Hi Karen, 2pi is equal to 360 degrees. 15 degrees goes into 360 24 times, thus 1/24 * 2pi = pi/12. Hope that helps.

[isayayosboon]

can you tell me how can you get pie3-3-1+pie3 over 1-3. please

[simran_kaur]

we can do 3-3pi/4 for 15degree and what is the value of tan40 plz tell me

[dexter_us]

good!!!! i have watch your other videos, thanks for posting!

[Kyleman]

How can you suddenly divide with 1+tan pi/3*tan pi/4??? it doesn't make sense, it isn't equal to 1.

[jomi]

Would tan( 45 degrees - 30 degrees) work?

[-mathwatcher-]

2:10 Please tell me where those numbers came from. That's where I am lost, and I have a Trig test tomorrow..

[julioortiz]

Sorry, but you need to explain more. How did you get pie over 12?

[rainbowguppy]

How did you get pie over 12??? where did the 12 come from?