All SAT II Math I Resources
Example Questions
Example Question #21 : Number Theory
Simplify:
First remember the form of the complex number:
Where "a" is the "Real" part, and "b" is the imaginary part.
Only the real parts can be combined together, and only the imaginary parts can be combined together.
Therefore the equation becomes after distributing the negative sign:
Collect the real and imaginary terms together:
Giving the answer:
Example Question #1 : Equations With Complex Numbers
If and are real numbers, and , what is if ?
To solve for , we must first solve the equation with the complex number for and . We therefore need to match up the real portion of the compex number with the real portions of the expression, and the imaginary portion of the complex number with the imaginary portion of the expression. We therefore obtain:
and
We can use substitution by noticing the first equation can be rewritten as and substituting it into the second equation. We can therefore solve for :
With this value, we can solve for :
Since we now have and , we can solve for :
Our final answer is therefore
Example Question #1 : Equations With Complex Numbers
Solve for and :
Remember that
So the powers of are cyclic. This means that when we try to figure out the value of an exponent of , we can ignore all the powers that are multiples of because they end up multiplying the end result by , and therefore do nothing.
This means that
Now, remembering the relationships of the exponents of , we can simplify this to:
Because the elements on the left and right have to correspond (no mixing and matching!), we get the relationships:
No matter how you solve it, you get the values , .
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