Question

Can someone please help me with solving on the interval?

Answer 1

whats sin(pi/2)?

Answer 2

In degrees?

Answer 3

do you know the unit circle?

Answer 4

yeah

Answer 5

can you use it to find sin(pi/2)?

Answer 6

https://www.mathsisfun.com/geometry/images/circle-unit-radians.gif

Answer 7

its (0, 1) right?

Answer 8

its 1 for sin and 0 for cos

Answer 9

Yeah

Answer 10

so for sin(pi/2) just replace that with one in the equation and see if it equals 0

Answer 11

yep, it equals 0

Answer 12

great, that means x=pi/2 is a solution.

Answer 13

now try it with pi/6

Answer 14

(root3/2, 1/2)

Answer 15

ok, one is cos(pi/6) and the other is sin(pi/6). can you tell me which one represents sin(pi/6)?

Answer 16

(1/2)

Answer 17

Right?

Answer 18

yep, good job

Answer 19

do you know where those values come from? what the sine and cosine functions look like?

Answer 20

I think so, isn't cosine 1, 1 and sine 1, 2

Right?

Answer 21

ummm, i'm not sure what you mean

Answer 22

http://cf.ydcdn.net/1.0.1.30/images/main/sine%20curve.jpg

Answer 23

so that's what the sine function looks like

Answer 24

oh ok, I thought you meant something else

Answer 25

at pi/2 the height of the graph is at one

Answer 26

at pi/6 the height of the graph is at 1/2

Answer 27

wait so the first one is the answer?

Answer 28

we don't know that yet

Answer 29

try plugging in 1/2 for sinx in the equation and see if it equals 0

Answer 30

like we did before for sin(pi/2)

Answer 31

It equals 0

Answer 32

thats right, x=pi/6 is a solution

Answer 33

so what's sin(5pi/6)?

Answer 34

(1/2)

Answer 35

that's right, well done

Answer 36

So we have (pi/2), (pi/6), and (5pi/6) right?

Answer 37

yes

Answer 38

Thank you so much

Answer 39

no problem, have a good night.

Answer 40

You too