graph of sin(90-x): Desmos calculator returns wrong graph...?

[hndalama]

sin(90-x) = cosx but when I plot the graph of sin(90-x) in www.desmos.com/calculator , the graph given has (0, 0.894) as the y intercept. Why doesn't it show the graph of cosx?

 

[HallsofIvy]

That site assumes angles are in radians, not degrees. To graph sin(90- x) in degrees, replace it with $\displaystyle sin((\pi/180)(90- x))$. Also, in order to see the graph properly, on that website you will need to expand the x-axis to, say, -180 to 180.

 

[MarkFL]

sin(90-x) = cosx but when I plot the graph of sin(90-x) in www.desmos.com/calculator , the graph given has (0, 0.894) as the y intercept. Why doesn't it show the graph of cosx?

It may be that the calculator is in radian mode...try plotting:

$\displaystyle \displaystyle y=\sin\left(\frac{\pi}{2}-x\right)$