I don't know how this works

Question

elusive · Answer

attachment

princeharryyy · Answer

simple division 150/175.78125 = 0.85333333......

elusive · Answer

how is 150 ft equal to 175 sin(2theta) in the first place?

alekos · Answer

That's just the starting point

elusive · Answer

??

princeharryyy · Answer

because sin2theta lies between -1 and 1. SO it can always be equal.

princeharryyy · Answer

anything lesser than 1 when multiplied to the number will give a number less than that number.

elusive · Answer

I don't think I understand. 
How is 1 equal to 175 ft?

princeharryyy · Answer

175 * 0.8533333333 = 150

princeharryyy · Answer

so the value of sin2theta = 0.85333333....

alekos · Answer

Does that help?

princeharryyy · Answer

-1<  0.853333333..  <1

princeharryyy · Answer

value of sines always lies between -1 and 1

elusive · Answer

how can the units be the same?'

alekos · Answer

Makes sense to me but does @elusive understand

elusive · Answer

im still confused by how 150ft can be equal to 175??

alekos · Answer

It's not

princeharryyy · Answer

product of sin2theta and 175 is equal to  150

princeharryyy · Answer

where you have to calculate sin2theta

princeharryyy · Answer

units are same because sin2theta has no units

princeharryyy · Answer

@elusive

mathmate · Answer

The second line of the statement is not correct!
150 feet = 175.78125 feet * sin(2$\theta)$
Divide both sides by 175.78125 $feet$
gives 
150 feet / 175.78125 feet = sin(2$\theta)$
0.853333.... = sin(2$\theta)$
meaning that there is no unit on the left hand side.  Sin($2\theta)$ is a pure number.

elusive · Answer

hm...
Is it important to memorize every single trig identities?
This has something to do with that.. And I'm stuck because I did not memorize them

loser66 · Answer

I guess!! the problem is : |dw:1473337086683:dw|

elusive · Answer

i'll come back to this later. thnk you