How would i rearange this trig equation

3cos(x)=5

3cos(x) = 5

Divide by 3:

cos(x) = 5/3

Use arccos to solve:

x = arccos(5/3), which isn't possible, so there is no solution.

there is no real value of x so that 3cosx = 5

3cosx = 5
cosx = 5/3
x = arccos(5/3)
x = i * ln3

which is solely "imaginary", for lack of a better word
therefore, no REAL solution

Since cos(x) <= 1, 3*cos(x) <= 3

so 3*cos(x) = 5 has no solution (in real numbers)