Given pi2
Given pi/2<x<pi and sinx=3/5 calculate cotx.
Solution
We notice that the angle x is located in the 2nd quadrant, therefore the values of cotangent function are negative.
We know that cot x = cos x/sin x
We\'ll determine cos x, applying the Pythagorean identity:
(cos x)^2 + (sin x)^2 = 1
(cos x)^2 = 1 - (sin x)^2
(cos x)^2 = 1 - 9/25
(cos x)^2 = (25 - 9)/25
(cos x)^2 = 16/25
cos x = -4/5
We\'ll keep only the negative value for cos x, since x is in the second quadrant and cosine function is negative.
cot x = (-4/5)/(3/5)
cot x = -4/3
The value of cotangent function is: cot x = -4/3.

