Reference Angles and exact values

[intervade]

Ok, I keep coming up on these problems, reference angles are easy and I understand them, and why they work now.. The question I keep getting is find the exact value of a function without using a calculator.

sin(150 degrees)

that equals sin(40 degrees) , my book gives me an answer of 1/2 .. why is this 1/2? I understand we are doing this on a unit circle but can someone please explain!

thanks

 

[Deleted member 4993]

Ofind the exact value of a function without using a calculator.

sin(150 degrees)

that equals sin(40 degrees) <<< Incorrect - how did you come to that conclusion?

 

[Mrspi]

Ok, I keep coming up on these problems, reference angles are easy and I understand them, and why they work now.. The question I keep getting is find the exact value of a function without using a calculator.

sin(150 degrees)

that equals sin(40 degrees) , my book gives me an answer of 1/2 .. why is this 1/2? I understand we are doing this on a unit circle but can someone please explain!

thanks

How did you arrive at sin (150[sup:g56e4woq]o[/sup:g56e4woq]) = sin 40[sup:g56e4woq]o[/sup:g56e4woq]???

What is the reference angle for 150[sup:g56e4woq]o[/sup:g56e4woq]?

When you get the correct reference angle, I believe you'll also end up with the "book answer."

 

[intervade]

Ahh, mistype.. sin(150 degrees) = sin(30 degrees) ..

 

[Deleted member 4993]

Ahh, mistype.. sin(150 degrees) = sin(30 degrees) ..

So then how much is sin(30) - you should know this value from using unit circle.