Question

Refer to the triangle and compute the quantities indicated. (Enter your answers in exact form.)

a) sin(s/2)

b) cos(s/2)

Answer 1

I need heeeeeeeelp.

Answer 2

Sine = Opp / Hypotenuse Cosine = Adj / Hypotenuse.....Need to determine your hypotenuse first

Answer 3

Ok, so what is the hypotenuse?

Answer 4

a^2 +b^2=c^2

Answer 5

wouldn't it be 26?

Answer 6

Yes

Answer 7

Ok after that what do I do?

Answer 8

SIne(s) = opposite side / hypotenuse

Answer 9

Opposite side from the s angle

Answer 10

ok, but when do I have to divide by 2?

Answer 11

Since it's sin (s/2)

Answer 12

I assume so ....

Answer 13

Strange question...I would compute my value for s, then divide by 2....do they want you to convert to degrees?

Answer 14

Nope, they want it in fraction form, like in exact form. It's webassign and they have a lot of requirements.

Answer 15

You should probably use the half-angle formulas.

\(\sin(s/2) = \sqrt{\dfrac{1-\cos(s)}{2}}\) for triangles.

\(\cos(s/2) = \sqrt{\dfrac{1+\cos(s)}{2}}\) for triangles.

Answer 16

Yep..tkbunny is right

Answer 17

determine cos(s) by adjacent / hypotenuse then plug into the formulas above....sorry I forgot about 1/2 angles

Answer 18

I'm still slightly confused, like how exactly I'm I supposed to plug it in the calculator?

Answer 19

cosine (10/26) what do you get?

Answer 20

You don't use a calculator. Just write down the exact expression.

\(\cos(s) = 10/26 = 5/13\)

\(\sin(s/2) = \sqrt{\dfrac{1-(5/13)}{2}} = \sqrt{\dfrac{4}{13}} = \dfrac{2}{\sqrt{13}}\)

Do the same for the cosine.