Evaluate
-\frac{\sqrt{2}}{2}\approx -0.707106781
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\sin(270+45)=\sin(270)\cos(45)+\sin(45)\cos(270)
Use \sin(x+y)=\sin(x)\cos(y)+\sin(y)\cos(x) where x=270 and y=45 to obtain the result.
-\cos(45)+\sin(45)\cos(270)
Get the value of \sin(270) from trigonometric values table.
-\frac{\sqrt{2}}{2}+\sin(45)\cos(270)
Get the value of \cos(45) from trigonometric values table.
-\frac{\sqrt{2}}{2}+\frac{\sqrt{2}}{2}\cos(270)
Get the value of \sin(45) from trigonometric values table.
-\frac{\sqrt{2}}{2}+\frac{\sqrt{2}}{2}\times 0
Get the value of \cos(270) from trigonometric values table.
-\frac{\sqrt{2}}{2}
Do the calculations.
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