the answer is -2 because 21-23 is a negative number
Standard Deviation, σ: 1.870828693387
Count, N: 4
Sum, Σx: 12
Mean, μ: 3
Variance, σ2: 3.5
<span>sin 90° = 1
</span>
cos 0° = 1
There's a simple formula : <em>sin θ = cos (90°- θ)</em> or <em>cos θ = sin (90°- θ) </em>
So : cos 0° = sin (90° - 0°) = sin 90° = 1
Well when two angles are supplementary they equal 180.
So if angle A is 80 degrees then that would mean that angle B equals 100 degrees.
Hope This Helped :)