Question

@kendricklamar2014

Answer 1

Did you get help with this, @Allieeslabae ?

Answer 2

No, could you help me?!

Answer 3

Sure. Be patient, keyboard won't get all letters tonight.

Answer 4

didyou notice there is a cos(theta) in both terms? First, try factoring the cos(theta) out of the left side.

Answer 5

You wind up with something of the FORM x(y+a)= 0. This is a really good form, because it will be zero if x is 0 (anything times zero is zero, right) OR when y=-a (so "(y+a)=0")
Makes ense?

Answer 6

Wait so I never got this during the lesson. Ill send the answer choices. @mjdennis and then can we jsut work backwards?

Answer 7

Okay so we're left with 2 sin(theta)+sqrt3=0?

Answer 8

It will take solving it 4 times per answer choice if you choose to brute force things that way.

Answer 9

Almost yes. one sec

Answer 10

You have cos(theta) * ( 2*sin(theta)+sqrt3) = 0
so anything that solves cos(theta) = 0 is an answer
OR anything that solves 2 sin(theta)+sqrt3=0 is ALSO an answer.

Answer 11

Easy part first. Name a couple theta values where cos(theta)=0

Answer 12

Almost as easy, solve 2 sin(theta)+sqrt3=0

Answer 13

Mmm lets remember we're talking to someone who sucks at math, what are you asking here?

Answer 14

NP. When you said "Okay so we're left with 2 sin(theta)+sqrt3=0?", you were correct.
SO let us focus on that first.

Answer 15

all you need is algebra for a minute. pretend it was 2x+sqrt3= 0
All you would do is is subtract sqrt3 from both sides, and divide by 2 right?

Answer 16

This is what I get: \[(\theta)=(-\pi/3\pm2\pi n), (4\pi)/(3\pm 2\pi n)\]

Answer 17

Wait so if I do it your way... When I subtract sqrt 3 from both sides I get 2x=sqrt3 correct? Then I divide by 2x?!

Answer 18

x=-sqrt3/2 ???

Answer 19

Right, so where is sin(theta) = -sqrt3/2?
-pi/3 and 5*pi/3 and 11*pi/3 etc.,
but you forgot there are two places for sin(theta) = -sqrt3/2

Answer 20

Wait so so far we have pi/2, 5pi/3, and ...yeah

Answer 21

Wow thank you! I got it, it's C!

Answer 22

WAIT, not C on the picture you originally attached1

Answer 23

Oh, really? Way to catch me before I turn it in.

Answer 24

Every answer has pi/2 and 3*pi/2. Forget those.
We know we have 5*pi/3 from your work, and A,B, and D have those.
In the picture I drew, there is 5*pi/3 on the right half of the circle and -2*pi/3 on the left.
What is a positve equivalent angle to -2*pi/3 ?

Answer 25

One moment.

Answer 26

I just multiplied it by 2... to get something equivalent and got: 4*pi/3

Answer 27

So it's A?!

Answer 28

That's what I got. So, yeah, brute force would have found the answer quickly after all. :-(

Answer 29

Good work, though! Any questions?

Answer 30

bwahahah! Thank you for all the help! xo No siree!