R = 500
To isolate the unknown quantity in trig problems, you can use
a process similar to the "magic circle."
E = 1000
First, determine the function formula which must be used.
(Assume the formula is for the cosine function.)
Now, place the formula, cos
, in a "magic triangle",
just as we place Ohm's law in a magic circle.
And in trigonometry,
It can be seen in the triangle that cos
and that x = cos x r.
Now, assuming the formula to be used is for the sine function,
place the formula,
in the triangle