Write the complex number -12+16i in trigonometric form r(cos theta+i sin theta), with theta in the interval

First identify which quadrant we are in:
x = real = -12
y = imaginary = 16
(-12,16) is in 2nd quadrant, this means theta is between 90 and 180.

Next calculate "r", which is distance from (-12,16) to origin:

Finally, calculate theta:

Note: when you put this in your calculator it will give you -53.13 (4th quadrant)
Just add 180 so that angle is in correct quadrant.
Final

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!