Question

plz help:using the fact that 15=45-30, determine the exact value of sin 15 in simplest radical form

Answer 1

@Hero plz help

Answer 2

sin(a - b) = sin(a)cos(b) - cos(a)sin(b)

Answer 3

is tht formula?

Answer 4

sin(45 - 30) = sin(45)*cos(30) - cos(45)*sin(30)

Answer 5

Yes that is the formula. All you have to do is just plug in the values and then simplify.

Answer 6

what do u do with 15?

Answer 7

Put it this way:

sin (15) = sin(45 - 30)
= sin(45)*cos(30) - cos(45)*sin(30)

Answer 8

so this is wht I got:

Answer 9

sin15=sin(15)=(raidcal2/2)(radical3/2)-(raidcal2/2)(radical1/2)

Answer 10

Okay, so simplify it further

Answer 11

sin(45 - 30) should stay as 45 - 30

Answer 12

I shuld multiply radical2/2*radical3/2

Answer 13

Yes, you should

Answer 14

i got 1.224744871

Answer 15

Not into decimals though

Answer 16

raidcal6/2?

Answer 17

it tht rit?

Answer 18

Should be \(\dfrac{\sqrt{6}}{4}\) for that part

Answer 19

ye thts what i meant

Answer 20

so i got sin15=sin(15)=radical4/4?

Answer 21

good?

Answer 22

@Hero

Answer 23

Not exactly

Answer 24

You should have ended up with \(\sin(15) = \dfrac{\sqrt{6} - \sqrt{2}}{4}\)

Answer 25

oh thts my final answer? i cnt subtract radical6-radical2? bc the denominators are same

Answer 26

How would you subtract \(\sqrt{6} - \sqrt{2}\)? Remember, you can't subtract if there is no property that allows you to.

Answer 27

You can only do what the properties say that you can do.

Answer 28

If you can find a radical or exponential property that allows you to subtract in that manner, then you can. Otherwise, you can't.

Answer 29

oh got so thts my finasl answer? rit?

Answer 30

@Hero

Answer 31

Yes, that is the final answer

Answer 32

thnks so much ur awesome! i appreciate ur time and help