trigonometry - Solve trigonometrics equations in Matlab -

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i'm trying solve t trigonometric equations in matlab, i.e. 7*cos(t) + 5*sin(t) = 0. solve as: sin(t)/cos(t) = -7/5 , find arctan(-7/5) = -0.9505.

i have tried on matlab using solve function:

syms t theta = solve(7*cos(t) + 5*sin(t)==0, t); disp(theta);

but -(log(- 12/37 - (35*i)/37)*i)/2 instead of -0.9505. explain me why answer solve , how -0.9505?

the expression exact result, expressed symbolically (due use of syms).

to make matlab display result in format looking use double(theta)

which should give you:

double(theta)  ans =     -0.9505

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