How to rearrange y = - A cos B (x-c) + D to make x the subject?

y = -A cos B (x-C) + D
y - D = -A cos B (x-C)
D - y = A cos B (x-C)
(D-y)/A = cos B (x-C)
cos⁻¹((D-y)/A)) = B(x-C)
cos⁻¹((D-y)/A)) / B = x - C
x = C + cos⁻¹((D-y)/A)) / B

y = - A cos B (x-c) + D
y - D = -A cos B (x-c)
(y-D)/-A = cos B (x-c)
arccos((y-D)/-A)) = B(x-c)
(arccos((y-D)/-A)))/B = x-c
(arccos((y-D)/-A)))/B - c = x

arccos is the same thing as cos^-1, or inverse of cos.

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