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anonymous
 4 years ago
if sin25=a and cos40=b, express cos140 / (tan205) (cos385) in terms of a and b
anonymous
 4 years ago
if sin25=a and cos40=b, express cos140 / (tan205) (cos385) in terms of a and b

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anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0Is it \( \large { \cos140^\circ} \over { (\tan 205^\circ) (\cos 385^\circ)} \) ?

ash2326
 4 years ago
Best ResponseYou've already chosen the best response.4We have \[\frac{cos 140}{tan 205 * cos 385}\] tan (205)=tan(180+25)= tan (25) =\(\frac{sin 25}{cos 25}\) cos 140= cos(18040)=  cos 40 cos 385=cos(360+25)=cos 25 substituting these in the given expression \[\frac{\cos 40}{\frac{sin 25}{cos 25} * cos 25}\] now we cancel the cos 25 \[\frac{\cos 40}{\frac{sin 25}{\cancel{cos 25}} * \cancel{cos 25}}\] we have now \[\frac{\cos 40}{\sin25}\] so we get \[\frac{b}{a}\]

Mertsj
 4 years ago
Best ResponseYou've already chosen the best response.0cos 140 = cos 40 tan205=tan25 cos385=cos25 \[\frac{\cos40}{\frac{\sin25}{\cos25}\cos25}\]

ash2326
 4 years ago
Best ResponseYou've already chosen the best response.4welcome lovampire_lsc, Did you understand the solution?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0ys, super clearly thanks a lot
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