How can you express the complex number z = 2 + 3i in the form z = r(cos x + i sinx)

First you want to draw the complez number on to an argand diagram, using which you will find the modulus and argument. This is how to do so: The modulus is to be obtained using pythagoras (which will be easier to describe using the diagram). The argument will be obtained using trigonometric rules since the line on the argand diagran will be a right angled triangle. Then the modulus and argument will be written into the form : z = [z](cos(argz) + i sin(argz)