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tan^2(60) + 4cos^2(45)  9tan^2(30)  8sin^2(30)
The answer is zero but why!? i need step by step solution please
 one year ago
 one year ago
tan^2(60) + 4cos^2(45)  9tan^2(30)  8sin^2(30) The answer is zero but why!? i need step by step solution please
 one year ago
 one year ago

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ShadowysBest ResponseYou've already chosen the best response.0
why can't you just plug the whole thing into your calculator?
 one year ago

CEBS95Best ResponseYou've already chosen the best response.0
because in the exam they already give you the answer, you have to do the procedure
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
tan60 = \(\sqrt{3}\) cos45 = \(\frac{1}{\sqrt2}\) tan30 = \(\frac{1}{\sqrt3}\) sin30 = 1/2 These are all special angles and you should remember them.
 one year ago

CEBS95Best ResponseYou've already chosen the best response.0
yes i know them but i just continue to get 6 instead of 0
 one year ago

ShadowysBest ResponseYou've already chosen the best response.0
I'm getting zero just fine though. note the squares.
 one year ago

CEBS95Best ResponseYou've already chosen the best response.0
tan^2(60) = 3 ? 4cos^2(45) = 4 ?
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
4cos^2(45) = 4 (1/2) = ...?
 one year ago

CEBS95Best ResponseYou've already chosen the best response.0
my math base is not good, that's the reason i wrote step by step solution
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
\[cos45 =\frac{1}{\sqrt2}\]\[cos^245 =(\frac{1}{\sqrt2})^2 = \frac{1}{2}\]\[4cos45 =4(\frac{1}{2}) = ...?\]
 one year ago

winterfezBest ResponseYou've already chosen the best response.0
\[\frac{ \sin ^{2} (60)}{ \cos ^{2}(60)}+4\cos ^{2}(45)9\frac{ \sin ^{2}(30) }{ \cos ^{2}(30) }8\sin ^{2}(30)\]
 one year ago

winterfezBest ResponseYou've already chosen the best response.0
dw:1355048071288:dw
 one year ago

CEBS95Best ResponseYou've already chosen the best response.0
i found in my book that cos 45 = \[\frac{ \sqrt{2} }{ 2}\]
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
\[\frac{1}{\sqrt2}=\frac{1}{\sqrt2}\times \frac{\sqrt2}{\sqrt2}=\frac{\sqrt2}{\sqrt2^2} = \frac{\sqrt2}{2}\] Just rationalization.
 one year ago

CEBS95Best ResponseYou've already chosen the best response.0
9tan^2(30) = \[\tan( 30) = \frac{ \sqrt{3} }{ 3 } ; \tan ^{2}(30) = 3/9 = 1/3 \]
 one year ago

CEBS95Best ResponseYou've already chosen the best response.0
9tan^2(30)  8sin^2(30) = 3  8 = 5, at the end that will give me 5 (5) that equals 10
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
8 sin ^2 (30) = 8 (1/2)^2 = 8 (1/4) = ...
 one year ago

CEBS95Best ResponseYou've already chosen the best response.0
still, 32 = 1, 51 = 4
 one year ago

winterfezBest ResponseYou've already chosen the best response.0
dw:1355049445375:dw look at this one to see how i get 0
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
tan^2(60) + 4cos^2(45)  9tan^2(30)  8sin^2(30) tan^2(60) = \(\sqrt3^2\) = ... 4cos^2(45) = 4\((\frac{1}{\sqrt2})^2\) = 4(1/2) = ...  9tan^2(30) = 9 \((\frac{1}{\sqrt3})^2\) = 9 (1/3) = ...  8sin^2(30) = 8 (1/2)^2 = 8 (1/4) = ... Sum up the four answers.
 one year ago

winterfezBest ResponseYou've already chosen the best response.0
dw:1355049643294:dw
 one year ago

CEBS95Best ResponseYou've already chosen the best response.0
zero! nice thanks calisto
 one year ago

CallistoBest ResponseYou've already chosen the best response.2
 30  45  60  sin  \(\frac{1}{2}\)  \(\frac{1}{\sqrt2} /\frac{\sqrt2}{2} \)  \(\frac{\sqrt3}{2}\)  cos  \(\frac{\sqrt3}{2}\)  \(\frac{1}{\sqrt2} /\frac{\sqrt2}{2} \)  \(\frac{1}{2}\)  tan  \(\frac{1}{\sqrt3} /\frac{\sqrt3}{3} \)  1  \(\sqrt{3}\)
 one year ago

CEBS95Best ResponseYou've already chosen the best response.0
yes, with practice i will memorise the terms
 one year ago
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