HELP!! What is the exact value of Tangent (pi/12)
A. StartFraction 1 Over 2 + StartRoot 3 EndRoot EndFraction
B. StartFraction 1 Over StartRoot 3 EndRoot EndFraction
C. StartFraction 3 Over StartRoot 3 EndRoot EndFraction
D. StartFraction 1 Over 2 minus StartRoot 3 EndRoot EndFraction

HELP What is the exact value of Tangent pi12 A StartFraction 1 Over 2 StartRoot 3 EndRoot EndFraction B StartFraction 1 Over StartRoot 3 EndRoot EndFraction C S class=

Respuesta :

Answer:

2 - sqrt(3)

Step-by-step explanation:

Split pi/12 into two angles where the values of the six trigonometric functions are known.

tan (pi/4 - pi/6)

Apply the difference of angles identity

[tex]\frac{tan(pi/4) - tan(pi/6)}{1 + tan(pi/4)tan(pi/6)}[/tex]

tan(pi/4) = 1 , tan(pi/6) = (sqroot3)/3

Plug in and Simplify

[tex]\frac{1-\frac{\sqrt{3} }{3} }{1+1\frac{\sqrt{3} }{3} }[/tex]

[tex]\frac{\frac{3-\sqrt{3} }{3} }{\frac{3+\sqrt{3} }{3} }[/tex]

[tex]\frac{3-\sqrt{3} }{3} *\frac{3}{3+\sqrt{3} }[/tex]

[tex]\frac{3-\sqrt{3} }{3+\sqrt{3}}[/tex] Need to multiply this by [tex]\frac{3+\sqrt{3} }{3+\sqrt{3} }[/tex]

Expand and simplify numerator: [tex]\frac{6}{(3+\sqrt{3} )^{2} }[/tex]

Expand and simplify denominator: [tex]\frac{6}{12+6\sqrt{3}}[/tex]

Cancel the common factor: [tex]\frac{1}{2+\sqrt{3}}[/tex]