Question

Find an exact value. tangent of seven pi divided by twelve

Answer 1

Answer: negative 2 minus radical 3

Step-by-step explanation:

We can use the tangent half-angle formula to find the exact value of tangent of 7π/12:

tan(θ/2) = ±√[(1-cosθ)/1+cosθ)]

Here, θ = 7π/6, and cos(7π/6) = -sqrt(3)/2.

Substituting these values, we get:

tan(7π/12) = ±√[(1-(-sqrt(3)/2))/(1+(-sqrt(3)/2))]

= ±√[(2+sqrt(3))/(2-sqrt(3))]

Multiplying the numerator and denominator by (2+sqrt(3)), we get:

= ±√[(2+sqrt(3))^2/(4-3)]

= ±√[(2+sqrt(3))^2]

= ±(2+sqrt(3))

Since 7π/12 lies in the second quadrant, and tangent is negative in the second quadrant, the exact value of tangent of 7π/12 is - (2+√3)

Answer 2

tan
(
7
π
12
)
=
−
(
2
+
√
3
)
Step-by-step explanation:
tan
(
7
π
12
)
=
tan
(
π
−
5
π
12
)
= #-tan((5pi)/12)
=
−
tan
(
3
π
12
+
2
π
12
)
=
−
tan
(
π
4
+
π
6
)
Now using
tan
(
A
+
B
)
=
tan
A
+
tan
B
1
−
tan
A
tan
B
=
−
tan
(
π
4
)
+
tan
(
π
6
)
1
−
tan
(
π
4
)
tan
(
π
6
)
=
−
1
+
1
√
3
1
−
1
×
1
√
3
Multiplying numerator and denominator by
√
3
=
−
√
3
+
1
√
3
−
1
=
−
(
√
3
+
1
)
2
(
√
3
−
1
)
(
√
3
+
1
)
=
−
3
+
1
+
2
√
3
3
−
1
=
−
(
2
+
√
3