Heya! Ok, here is the exercise: Thanks in Advance!
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why?
Originally Posted by skeeter why? Where did u get that?
Originally Posted by JohnTerry Where did u get that? what's the relationship between angles and ?
Originally Posted by skeeter what's the relationship between angles and ? But... Isn't smth like: cosB = π-cosA [in rad] cosB = 180-cosA [in degrees] How is cosB = -cosA ?
Originally Posted by JohnTerry But... Isn't smth like: \cos(\beta) = π-\cos(\alpha) [in rad] \cos(\beta) = 180-\cos(\alpha) [in degrees] How is \cos(\beta)= -\cos(\alpha)?
Originally Posted by skeeter Then, cosA= 3/√45 cosB= -(3/√45) ?
Originally Posted by JohnTerry Then, cosA= 3/√45 cosB= -(3/√45) ? yes ... you're welcome.
Originally Posted by skeeter yes ... you're welcome. Thanks, but in the book the answer is -(√5/5) and -(3/√45) is -(3√45/45)
Originally Posted by JohnTerry Thanks, but in the book the answer is -(√5/5) and -(3/√45) is -(3√45/45)
Originally Posted by skeeter I'm sorry, but can you explain please how you passed from ?
Originally Posted by JohnTerry I'm sorry, but can you explain please how you passed from ? now rationalize the denominator ...
Originally Posted by skeeter now rationalize the denominator ... Oh! Thanks! But can you please explain one more thing... ´ How did u get from and from
Mathwords: Sum/Difference Identities
Originally Posted by skeeter Mathwords: Sum/Difference Identities Thanks again, but how = What does (-1) and (0) mean?
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