Tan 3pi/4
The value of tan 3pi/4 is -1. Tan 3pi/4 radians in degrees is written as tan ((3π/4) × 180°/π), i.e., tan (135°). In this article, we will discuss the methods to find the value of tan 3pi/4 with examples.
- Tan 3pi/4: -1
- Tan (-3pi/4): 1
- Tan 3pi/4 in degrees: tan (135°)
What is the Value of Tan 3pi/4?
The value of tan 3pi/4 is -1. Tan 3pi/4 can also be expressed using the equivalent of the given angle (3pi/4) in degrees (135°).
We know, using radian to degree conversion, θ in degrees = θ in radians × (180°/pi)
⇒ 3pi/4 radians = 3pi/4 × (180°/pi) = 135° or 135 degrees
∴ tan 3pi/4 = tan 3π/4 = tan(135°) = -1
Explanation:
For tan 3pi/4, the angle 3pi/4 lies between pi/2 and pi (Second Quadrant). Since tangent function is negative in the second quadrant, thus tan 3pi/4 value = -1
Since the tangent function is a periodic function, we can represent tan 3pi/4 as, tan 3pi/4 = tan(3pi/4 + n × pi), n ∈ Z.
⇒ tan 3pi/4 = tan 7pi/4 = tan 11pi/4 , and so on.
Note: Since, tangent is an odd function, the value of tan(-3pi/4) = -tan(3pi/4).
Methods to Find Value of Tan 3pi/4
The tangent function is negative in the 2nd quadrant. The value of tan 3pi/4 is given as -1. We can find the value of tan 3pi/4 by:
- Using Unit Circle
- Using Trigonometric Functions
Tan 3pi/4 Using Unit Circle
To find the value of tan 3π/4 using the unit circle:
- Rotate ‘r’ anticlockwise to form 3pi/4 angle with the positive x-axis.
- The tan of 3pi/4 equals the y-coordinate(0.7071) divided by the x-coordinate(-0.7071) of the point of intersection (-0.7071, 0.7071) of unit circle and r.
Hence the value of tan 3pi/4 = y/x = -1
Tan 3pi/4 in Terms of Trigonometric Functions
Using trigonometry formulas, we can represent the tan 3pi/4 as:
- sin(3pi/4)/cos(3pi/4)
- ± sin(3pi/4)/√(1 - sin²(3pi/4))
- ± √(1 - cos²(3pi/4))/cos(3pi/4)
- ± 1/√(cosec²(3pi/4) - 1)
- ± √(sec²(3pi/4) - 1)
- 1/cot(3pi/4)
Note: Since 3pi/4 lies in the 2nd Quadrant, the final value of tan 3pi/4 will be negative.
We can use trigonometric identities to represent tan 3pi/4 as,
- cot(pi/2 - 3pi/4) = cot(-pi/4)
- -cot(pi/2 + 3pi/4) = -cot 5pi/4
- -tan (pi - 3pi/4) = -tan pi/4
☛ Also Check:
Examples Using Tan 3pi/4
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Example 1: Find the value of (2 sin (3pi/8) cos (3pi/8) sec (3pi/4)). [Hint: Use tan 3pi/4 = -1]
Solution:
Using sin 2a formula,
2 sin (3pi/8) cos (3pi/8) = sin (2 × 3pi/8) = sin 3pi/4
⇒ 2 sin (3pi/8) cos (3pi/8) sec(3pi/4) = sin(3pi/4) sec(3pi/4)
= sin(3pi/4)/cos(3pi/4) = tan 3pi/4
⇒ (2 sin (3pi/8) cos (3pi/8) sec(3pi/4)) = -1 -
Example 2: Find the value of tan 3pi/4 if cot 3pi/4 is -1.
Solution:
Since, tan 3pi/4 = 1/cot(3pi/4)
⇒ tan 3pi/4 = 1/(-1) = -1 -
Example 3: Using the value of tan 3pi/4, solve: (sec²(3pi/4) - 1).
Solution:
We know, (sec²(3pi/4) - 1) = (tan²(3pi/4)) = 1
⇒ (sec²(3pi/4) - 1) = 1
FAQs on Tan 3pi/4
What is Tan 3pi/4?
Tan 3pi/4 is the value of tangent trigonometric function for an angle equal to 3π/4 radians. The value of tan 3pi/4 is -1.
How to Find Tan 3pi/4 in Terms of Other Trigonometric Functions?
Using trigonometry formula, the value of tan 3pi/4 can be given in terms of other trigonometric functions as:
- sin(3pi/4)/cos(3pi/4)
- ± sin(3pi/4)/√(1 - sin²(3pi/4))
- ± √(1 - cos²(3pi/4))/cos(3pi/4)
- ± 1/√(cosec²(3pi/4) - 1)
- ± √(sec²(3pi/4) - 1)
- 1/cot(3pi/4)
☛ Also check: trigonometric table
What is the Value of Tan 3pi/4 in Terms of Cosec 3pi/4?
Since the tangent function can be represented using the cosecant function, we can write tan 3pi/4 as -1/√(cosec²(3pi/4) - 1). The value of cosec 3pi/4 is equal to 1.41421.
What is the Value of Tan 3pi/4 in Terms of Sin 3pi/4?
Using trigonometric identities, we can write tan 3pi/4 in terms of sin 3pi/4 as, tan(3pi/4) = -sin(3pi/4)/√(1 - sin²(3pi/4)) . Here, the value of sin 3pi/4 is equal to 1/√2.
How to Find the Value of Tan 3pi/4?
The value of tan 3pi/4 can be calculated by constructing an angle of 3π/4 radians with the x-axis, and then finding the coordinates of the corresponding point (-0.7071, 0.7071) on the unit circle. The value of tan 3pi/4 is equal to the y-coordinate(0.7071) divided by the x-coordinate (-0.7071). ∴ tan 3pi/4 = -1
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