Question

http://prntscr.com/9auym5
Tried using quadratic formula and got a nonreal answer, what the heck o-0

Answer 1

Okay, yes; definitely a nonreal answer?! http://prntscr.com/9auzc7

Answer 2

graph the left side as a function

https://www.desmos.com/calculator

then see where it crosses the x axis

Answer 3

you can click on the roots to have the coordinates show up

you'll have to zoom in to get more decimal places

Answer 4

http://prntscr.com/9auzw8
I think this website hates me.

Answer 5

you have to type in `(sin(x))^2` instead of sin^2(x)

Answer 6

ah

Answer 7

http://prntscr.com/9av0c3 0-0

Answer 8

don't enter the `=0` part

just the left hand side

Answer 9

oh, okay

Answer 10

I got the equation in, what should I do now lol

Answer 11

I never used this site before, but it seems pretty nifty. Thanks for the reference :)

Answer 12

click on the roots to have the coordinates show up

roots = x intercepts

Answer 13

Okay

Answer 14

like this? http://prntscr.com/9av0wy

Answer 15

wherever the graph of f(x) crosses the x axis is going to represent an approximate solution to f(x) = 0

Answer 16

yeah but keep in mind that 0 <= x < 2pi

Answer 17

http://prntscr.com/9av12t

Answer 18

still not in the right interval

Answer 19

eh o_o

Answer 20

I'm lost then xD

Answer 21

No, I get that; but I'm not sure how to apply the limits to the graph

Answer 22

x has to be both

larger than 0
AND
smaller than 2pi = 6.28 approx

Answer 23

ah

Answer 24

you can click and drag to move the window of the graph

Answer 25

http://prntscr.com/9av1mr
these?

Answer 26

yep now just zoom in until it shows you 4 decimal places

Answer 27

alright!

Answer 28

http://prntscr.com/9av1wa
Wow, this is really helpful, thanks @jim_thompson5910

Answer 29

you nailed them both

Answer 30

if sin(x) = u

u^2 - 3u - 3 = 0

\[u = \frac{ 3 \pm \sqrt{9-4*1*(-3)} }{ 2 }\]

one works

Answer 31

sin(x) = u

sin^(-1)(u) = x

Answer 32

._.;

Answer 33

@DanJS is showing how to find the solutions without graphing

Answer 34

Ah.
It asked for graphing though ^^;

Answer 35

the negative one , subtracting the root, will give you a good answer in the 0 to 2pi interval

Answer 36

O_O okay

Answer 37

Well I'd give you a medal but I already gave one to jim ;-;
I'm sorry!

Answer 38

inverse sin of that , you get something like 0.91291


the other is a neg angle

Answer 39

not real

Answer 40

ha, thats fine,

Answer 41

>.<;;

Answer 42

But thank you for the info :D