IS my answer right ?????????????

Question

anonymous · Answer

Two triangles can be formed with the given information. Use the Law of Sines to solve the triangles. 

B = 46°, a = 12, b = 11

anonymous · Answer

A = 51.7°, C = 82.3°, c = 15.2; A = 128.3°, C = 5.7°, c = 1.5

anonymous · Answer

@Anu2401 @e.mccormick @cwrw238 @Falco276 @IrishBoy @ivandelgado @johnweldon1993 @kropot72 @ogkat @Preetha @RaphaelFilgueiras @thomaster

anonymous · Answer

can any help

e.mccormick · Answer

First OK.  Still checking second.

anonymous · Answer

ok thnx

e.mccormick · Answer

Helps when I put the riht numbers in the calculator.... looks good.

anonymous · Answer

wow thnx i have one more that im confuse about @e.mccormick  if you dont mind

anonymous · Answer

Find the fourth roots of 256(cos 280° + i sin 280°).

e.mccormick · Answer

DeMoivre’s Theorem

Let $z = r[\cos(θ) + i\sin(θ)]$ and n be a positive integer. Then $z^n=r^n[\cos(n\theta)+i\sin(n\theta)]$

anonymous · Answer

Let y=256(cos 280+i sin 280)
Now this[(cos 280+i sin 280)] can be written in exponential form as exp^(i*280)

We need to find y^(1/4)
Hence 
=>[256*exp^(280i)]^(1/4)
=>4*exp^(70i)
=>4(cos70+isin70) Ans

anonymous · Answer

i dont understand the formula the second one what is r 256

e.mccormick · Answer

So you do your $256^4$ and put that out front, then multiply the angles by 4, then simplify a bit (can reduce the angles to $0^\circ\le 360^\circ$

e.mccormick · Answer

Oops.  Yah, root....  I want the wrong direction.

anonymous · Answer

ok @Anu2401 what is after that

e.mccormick · Answer

Anu2401's /(r^{\frac{1}{4}} is right.  Going to the root rather than the power.

e.mccormick · Answer

$r^{\frac{1}{4}}$

anonymous · Answer

so is he right at that step

anonymous · Answer

im trying to take notes

anonymous · Answer

@Easycheddar Yes the solution is correct . Just go through de-moiver's theorem once .... Google It  :)

e.mccormick · Answer

Absolutly.  Because they said 4th root.  It is the same thing as this:$$\sqrt[4]{x}=x^{\frac{1}{4}}$$

anonymous · Answer

http://en.wikipedia.org/wiki/De_Moivre's_formula See application part

anonymous · Answer

ok so that the solution now i just need to do the therom

e.mccormick · Answer

I went tot he 4th power in my explanation... the question aid 4th root.  My mistake there.

anonymous · Answer

so what the answer cause i am getting something crazy @e.mccormick  and @Anu2401

anonymous · Answer

U can put the value of cos 70 & Sin 70 in last step . Use a calculator to find the values of those

e.mccormick · Answer

Did you start with:
$$256^{\frac{1}{4}}\left(\cos \frac{280^\circ}{4} + i \sin \frac{280^\circ}{4}\right)$$And follow how Anu2401 did it?  Also, is your calculator in Degrees or Radians mode?