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.