Is sin(3.6) Negative? Exploring Trigonometric Functions

  • B
  • Thread starter Chadi B Ghaith
  • Start date
  • Tags
    Negative
In summary, the reason why sin(3.6) is negative is because 3.6 is in radian measure, and in quadrant III where sine values are negative. It may seem confusing because in degrees, sin(3.6) is greater than -0, but this is due to the difference in measurement units.
  • #1
Chadi B Ghaith
35
4
Why is sin(3.6) Negative? Why is sin(3.6) negative? It makes no sense. It should be positive between -90 and 90 degrees.
 
Last edited by a moderator:
Mathematics news on Phys.org
  • #2
It makes sense if 3.6 is in radian.
 
  • Like
Likes Chadi B Ghaith
  • #3
Chadi B Ghaith said:
Why is sin(3.6) NEGATIVE? Why is sin(3.6) negative? It makes no sense. It should be positive between -90 and 90 degrees.
sin(3.6°) > -0, but 3.6 by itself is considered to be in radian measure.

Also,if x is between -90° and 0°, sin(x) is negative.
 
  • #4
Mark44 said:
sin(3.6°) > -0, but 3.6 by itself is considered to be in radian measure.

Also,if x is between -90° and 0°, sin(x) is negative.

Thank you Mark44.
 
  • #5
Because, π<3.6<3π/2 ... 3.6 radians lies in quadrant III where sine values are negative.
 

1. Why is the sine of 3.6 negative?

The sine of a given angle is determined by the y-coordinate of the point where the terminal side of the angle intersects with the unit circle. In the case of 3.6 degrees, this point falls in the fourth quadrant of the unit circle, where the y-coordinate is negative. Therefore, the sine of 3.6 is negative.

2. Can the sine of any angle be negative?

Yes, the sine of any angle can be negative. It depends on the location of the angle's terminal side on the unit circle. If the terminal side falls in the second or third quadrant, the sine will be negative. If it falls in the first or fourth quadrant, the sine will be positive.

3. How do I determine the sign of sine for a given angle?

To determine the sign of sine for a given angle, you can either use a unit circle or a calculator. If using a unit circle, identify the quadrant where the angle's terminal side falls and determine the sign of the y-coordinate. If using a calculator, enter the angle and look for the sign of the resulting sine value.

4. Why is the sine of 180 degrees equal to 0?

The sine of an angle is defined as the ratio of the opposite side to the hypotenuse in a right triangle. In the case of 180 degrees, the opposite side is equal to the hypotenuse, resulting in a ratio of 1. Since the sine of 180 degrees is equal to 1, it is also equal to 0.

5. Is there a relationship between the sign of sine and the quadrant of an angle?

Yes, there is a relationship between the sign of sine and the quadrant of an angle. As mentioned earlier, if the terminal side of an angle falls in the second or third quadrant, the sine will be negative. If it falls in the first or fourth quadrant, the sine will be positive. This is due to the location of the angle's terminal side on the unit circle and the resulting y-coordinate value.

Similar threads

Replies
8
Views
940
Replies
2
Views
756
Replies
5
Views
2K
  • General Math
Replies
6
Views
1K
Replies
28
Views
2K
Replies
26
Views
3K
  • General Math
Replies
1
Views
3K
  • General Math
Replies
1
Views
1K
  • General Math
Replies
9
Views
2K
Back
Top