Trigonometry exact value (1 Viewer)

[nsbrando]

find exact value

tan45+tan60 Over 1-tan45 tan60

 

[zeebobDD]

using tan(a+b), = tan(45+60) = tan(105)

 

[Amleops]

Tan 45 = 1
Tan 60 = Root 3

From there you just substitute and simplify, which will require rationalising the denominator.

 

[Fus Ro Dah]

using tan(a+b), = tan(45+60) = tan(105)

No, that is not the exact value. You just simplified the expression.

 

[Timske]

<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{tan45 @plus; tan60}{1-tan45tan60} = \frac{1 @plus; \sqrt{3}}{1 - \sqrt{3}} = -2-\sqrt{3}" target="_blank"><img src="http://latex.codecogs.com/gif.latex?\frac{tan45 + tan60}{1-tan45tan60} = \frac{1 + \sqrt{3}}{1 - \sqrt{3}} = -2-\sqrt{3}" title="\frac{tan45 + tan60}{1-tan45tan60} = \frac{1 + \sqrt{3}}{1 - \sqrt{3}} = -2-\sqrt{3}" /></a>

 

[zeebobDD]

No, that is not the exact value. You just simplified the expression.

yeah thats true but tan(105) is exact too and equals -2-root3 , but yeah thats the way to do it

 

[Fus Ro Dah]

yeah thats true but tan(105) is exact too and equals -2-root3 , but yeah thats the way to do it

Okay, tell me how to prove that tan(105) is -2-root3 as you said?

Even OP's expression there is exact by your definition.

 

[Shadowdude]

using tan(a+b), = tan(45+60) = tan(105)

tan(a+b) and other compound angle formulae are 3u and above only.