Cos pi/2
The value of cos pi/2 is 0. Cos pi/2 radians in degrees is written as cos ((π/2) × 180°/π), i.e., cos (90°). In this article, we will discuss the methods to find the value of cos pi/2 with examples.
 Cos pi/2: 0
 Cos (pi/2): 0
 Cos pi/2 in degrees: cos (90°)
What is the Value of Cos pi/2?
The value of cos pi/2 is 0. Cos pi/2 can also be expressed using the equivalent of the given angle (pi/2) in degrees (90°).
We know, using radian to degree conversion, θ in degrees = θ in radians × (180°/pi)
⇒ pi/2 radians = pi/2 × (180°/pi) = 90° or 90 degrees
∴ cos pi/2 = cos π/2 = cos(90°) = 0
Explanation:
For cos pi/2, the angle pi/2 lies on the positive yaxis. Thus, cos pi/2 value = 0
Since the cosine function is a periodic function, we can represent cos pi/2 as, cos pi/2 = cos(pi/2 + n × 2pi), n ∈ Z.
⇒ cos pi/2 = cos 5pi/2 = cos 9pi/2 , and so on.
Note: Since, cosine is an even function, the value of cos(pi/2) = cos(pi/2) = 0.
Methods to Find Value of Cos pi/2
The value of cos pi/2 is given as 0. We can find the value of cos pi/2 by:
 Using Trigonometric Functions
 Using Unit Circle
Cos pi/2 in Terms of Trigonometric Functions
Using trigonometry formulas, we can represent the cos pi/2 as:
 ± √(1sin²(pi/2))
 ± 1/√(1 + tan²(pi/2))
 ± cot(pi/2)/√(1 + cot²(pi/2))
 ±√(cosec²(pi/2)  1)/cosec(pi/2)
 1/sec(pi/2)
Note: Since pi/2 lies on the positive yaxis, the final value of cos pi/2 is 0.
We can use trigonometric identities to represent cos pi/2 as,
 cos(pi  pi/2) = cos pi/2
 cos(pi + pi/2) = cos 3pi/2
 sin(pi/2 + pi/2) = sin pi
 sin(pi/2  pi/2) = sin 0
Cos pi/2 Using Unit Circle
To find the value of cos π/2 using the unit circle:
 Rotate ‘r’ anticlockwise to form pi/2 angle with the positive xaxis.
 The cos of pi/2 equals the xcoordinate(0) of the point of intersection (0, 1) of unit circle and r.
Hence the value of cos pi/2 = x = 0
☛ Also Check:
Examples Using Cos pi/2

Example 1: Find the value of 2 cos(pi/2)/3 sin(pi/2).
Solution:
Using trigonometric values, we know, cos(pi/2) = 0 and sin(pi/2) = 1.
⇒ Value of 2 cos(pi/2)/3 sin(pi/2) = 0 
Example 2: Simplify: 8 (cos(pi/2)/cos(0))
Solution:
We know cos pi/2 = 0 and cos 0 = 1
⇒ 8 (cos(pi/2)/cos(0)) = 0 
Example 3: Find the value of cos pi/2 if sin pi/2 is 1 and cot pi/2 = 0.
Solution:
Since, cot pi/2 = cos(pi/2)/sin(pi/2)
⇒ cos pi/2 = 0
FAQs on Cos pi/2
What is Cos pi/2?
Cos pi/2 is the value of cosine trigonometric function for an angle equal to π/2 radians. The value of cos pi/2 is 0.
What is the Value of Cos pi/2 in Terms of Tan pi/2?
We know, using trig identities, we can write cos pi/2 as 1/√(1 + tan²(pi/2)).
How to Find Cos pi/2 in Terms of Other Trigonometric Functions?
Using trigonometry formula, the value of cos pi/2 can be given in terms of other trigonometric functions as:
 ± √(1sin²(pi/2))
 ± 1/√(1 + tan²(pi/2))
 ± cot(pi/2)/√(1 + cot²(pi/2))
 ±√(cosec²(pi/2)  1)/cosec(pi/2)
 1/sec(pi/2)
☛ Also check: trigonometry table
How to Find the Value of Cos pi/2?
The value of cos pi/2 can be calculated by constructing an angle of π/2 radians with the xaxis, and then finding the coordinates of the corresponding point (0, 1) on the unit circle. The value of cos pi/2 is equal to the xcoordinate (0). ∴ cos pi/2 = 0.
What is the Value of Cos pi/2 in Terms of Cosec pi/2?
Since the cosine function can be represented using the cosecant function, we can write cos pi/2 as [√(cosec²(pi/2)  1)/cosec pi/2]. The value of cosec pi/2 is equal to 1.
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