Question

use a half- angle formula to find the exactly value of the expression...:
Sin5 pies/12... can someone help me step by step

Answer 1

Do you know the half-angle formulas?

Answer 2

yes, i do...

Answer 3

What's the formula for sin(x/2)?

Answer 4

sin(x/2)=\[\pm \sqrt{1-cosx/2}\]

Answer 5

Ok. You missed the parentheses around 1-cosx, but yes that checks out.

Now, you know how to find the sin of half of an angle. You need to find sin(5pi/12). Can you see how this formula might help?

Answer 6

sin(x/2)=\[\pm \sqrt{1-cosx/2}\]

Answer 7

i dont know how to figure out:)..

Answer 8

sin(x/2)=\[\pm \sqrt{1-cosx/2}\]

Answer 9

in the unit circle dont have 5pi/12

Answer 10

They give you a hint to use the half-angle formula. What is 5pi/12 half of?

Answer 11

75 degree right

Answer 12

Yes, but leave it in terms of pi.

Answer 13

Wait. 75 degrees is still half of the angle we want. And keep it in radians. So 5pi/12 is half the angle we want. So what angle is 5pi/12 half of?

Answer 14

5pi/24

Answer 15

Wrong way.

Answer 16

i dont know

Answer 17

5pi/12 is half of the angle I've marked with a ?. How big is that angle?