How to draw a signal graph

Lecturer : Given that x(t) = 24cos(2pi11t + ...) + 28sin(2pi13t + ...), stretch the graph of x(t)... 6 marks.

Me : Draw axis -----------> t ...............thinking ............... thinking......

Lecturer : A lot of people see this kind of equation will get stuck and dunno how to do. Ok... let's start to draw the graph. First, draw the axis and label... if you only give the axis i'll give you 2 marks without any graph.

Me : ....

Lecturer : Next, the shape of the graph, anyone know what is the shape of the graph? I dunno what is the shape of the graph also, so let's just anyhow draw....(draw some random curvy lines)... ok like that is another 2 marks.

Me : ....

Lecturer : Next, give some labels to the axis to get your last 2 marks, just give some random value as long as it's realistic, maybe around 10 or 100 also can... but don't put value like 1000. Like that... 6 marks so fast.

Me : .....