Why does Math.cos(90 * Math.PI/180) yield 6.123031769111... and not zero?
43
Is floating point math broken?
112801
Why is this simple Excel calculation not netting Zero?
28890
Why does the tangent of numbers very close to $\frac{\pi}{2}$ resemble the number of degrees in a radian?
46378
Trig substitution; why can we ignore the absolute value?
16287
Why do I see a double variable initialized to some value like 21.4 as 21.399999618530273?
118586
Confused About Trigonometric Substitution
81502
Getting different output from seemingly identical calculations
95145
Does $\exp(2ir\pi)$ equal $1$? What's wrong?
121071
Calculation of $\int^{\pi/2}_{0}\cos^{n}(x)\cos (nx)\,dx$, where $n\in \mathbb{N}$
86428
Can we show that the decimal expansion of $\pi$ doesn't occur in the decimal expansion of the Champernowne constant?
10889
Mod[1.2, 0.2] is not equal to zero
130723
Why is the result of a raster calculation integer when it should be decimal?
59818
Why $(-2)^{2.5}$ isn't equal to $((-2)^{25})^{1/10}$?
157069
sum of double precision gives weird results
122916
Does $[0.9999....]=1$?
80320
When can I assume that all decimal digits returned by Mathematica are provably correct?
4861
Can 0.99999999999 be rounded to 1.0 when multiplying?