Write an expression using all six trigonometric functions such that the value of the expression is 3.

The trig functions that you need to deal with are
Sine
Cosine
Tangent
Cotangent
Cosecant
Secant

You need to write a single expression using all six trig functions such that the value of the expression equals 3.

To make this as simple as possible, the first thing I would do is look up the values of these functions and identify which ones are equal to either 1/2 or 1.0 or 2.0

sin(30º) = 1/2
sin(90º) = 1
cos(0º) = 1
cos(60º) = 1/2
tan(45º) = 1
csc(30º) = 2
csc(90º) = 1
sec(0º) = 1
sec(60º) = 2
cot(45º) = 1

If we only had to use three trig functions (sin, cos, tan), one possibility is
tan(45º) + cos(0º)/sin(30º) = 1 + 1/(1/2) = 1 + 2 = 3
noticed how I chose one each of the required functions and the operations so that the result = 3.

Now it is up to you to figure out how to combine all six trig functions so that they equal zero. There are many possibilities for you to choose from..