+129209 why is cos(90)=0? (degrees)
---------------------------------------------------------------------------------------------------------------------------
Think about this.....on a unit circle, the "x" value at pi/2 (90 degrees) = 0 and the value of "r" always = 1.
Since the cos(θ) = x / r then cos(90) = 0 / 1 = 0
Also, look at the cosine graph......notice at pi/2 that the curve crosses the x axis at that point, i.e., the value of the cosine at that point = 0
+129209 why is cos(90)=0? (degrees)
---------------------------------------------------------------------------------------------------------------------------
Think about this.....on a unit circle, the "x" value at pi/2 (90 degrees) = 0 and the value of "r" always = 1.
Since the cos(θ) = x / r then cos(90) = 0 / 1 = 0
Also, look at the cosine graph......notice at pi/2 that the curve crosses the x axis at that point, i.e., the value of the cosine at that point = 0
