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Inverse cosine in degrees


Y = acosd(X)



Y = acosd(X) returns the inverse cosine (cos-1) of the elements of X in degrees. The function accepts both real and complex inputs.

  • For real values of X in the interval [-1, 1], acosd(X) returns values in the interval [0, 180].

  • For values of X outside the interval [-1, 1] and for complex values of X, acosd(X) returns complex values.


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Verify that inverse cosine of 0 is exactly 90.

ans = 90

Show that the inverse cosine, followed by cosine, returns the original values of X.

cosd(acosd([2 3]))
ans = 1×2

     2     3

acosd([2 3]) returns two complex angles, which are then passed to the cosd function. cosd returns the original values, 2 and 3.

Input Arguments

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Cosine of angle, specified as a real-valued or complex-valued scalar, vector, matrix, or N-D array. The acosd operation is element-wise when X is non-scalar.

Data Types: single | double
Complex Number Support: Yes

Output Arguments

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Angle in degrees, returned as a real-valued or complex-valued scalar, vector, matrix, or N-D array of the same size as X.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

See Also

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Introduced before R2006a