Matlab code “glitch”? Matrix is turning into a single character, rather than staying a matrix [closed]

I am writing a matrix (a function) so I can plot it later on. It will go from theta2 = [-55:1:55] (-55 to 55) and the Y variable will be "theta4" which depends on theta2.

The highlited area in the picture should be in matrix form, but it is spitting out a single number, not 111 numbers! I have played around with it and it looks like when I add the ( / 2 .* a_t), it changes to single variable. (DIVIDE BY 2 * A_T)

How do I make it give me a matrix , not a single number?

theta2 =[-55:1:55];
theta4 = 2 * atand( (-b_t - sqrt(b_t.^2 - 4 .* a_t .* c_t)) / (2 .* a_t))
theta4 = 2 * atand( (-b_t - sqrt(b_t.^2 - 4 .* a_t .* c_t)) / (2 .* a_t))

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closed as off-topic by Dair, Quuxplusone, vnp, rolfl♦Feb 11 at 1:48

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