SIN(45) should equal COS(45) & TAN(45)=1 … But not on your calculator
Your trig functions are wack . . .
2 comments

Xenon commented
Actually they are wack. The trig functions are in radians, they expect you to use a # sign before number if you want to convert the number into radians (don't read help manual it is wrong/backwards). So for example: Sin(#45) = cos(#45) = 0.7071

CScotty commented
The units for the trig functions are radians, not degrees. So for example, instead of 45 (degrees) you need to use pi/4.