How Do You Square Cosine B?

chemic_23 · Jan 24, 2009

Homework Statement

Homework Equations

how do you square cosB?

The Attempt at a Solution

Galadirith · Jan 24, 2009

Hi chemic_23, well you haven't really asked a question. In answer to you how do you square [itex]cos\beta[/itex] (i assume that's what you meant) you can square it like any other number as [itex]\textbf{cos\beta}[/itex] will be a real number if beta is a real number. Is you question find the solutions to this equation, because there are an infinite number of them?

If you could clarify you question then I am sure you'll find the help you need :D

chemic_23 · Jan 24, 2009

I'm trying to understand this part of solution

Typed worked solution: Eq. 3 gives cos β = (4.00 − 2.00 cos α)/(0.6√20) and cos² β = 2.222 − 2.222 cos α + 0.5556 cos² α. Eq. 4 gives sin β = 0.7454 sin α and sin² β = 0.5556 sin² α = 0.5556 − 0.5556 cos² α. Adding and using sin² β + cos² β = 1 gives 1 = 2.778 − 2.222 cos α, cos α = 0.8002, α = 36.9°, then sin β = 0.7454 sin α gives β = 26.6°.

but I don't have any idea on how to square the cosB... It just came out with no detailed solution... please help

salman213 · Jan 24, 2009

if you have f(l) = (x + y) / z where x,y,z are constants

remember you can always change that to

x /z + y/z

and then what would be f^2 (l)

(x /z + y/z)^2 = (x /z + y/z)(x /z + y/z)

and you can expand that right?

chemic_23 · Jan 24, 2009

thanks:)

How Do You Square Cosine B?

Homework Statement

Homework Equations

The Attempt at a Solution

Discussion

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