All GRE Subject Test: Math Resources
Example Questions
Example Question #1 : Imaginary Numbers & Complex Functions
Example Question #6 : Imaginary Roots Of Negative Numbers
Example Question #71 : Algebra
The perfect square of 25 will go into 150
The square root of 25 is 5.
Example Question #12 : Imaginary Roots Of Negative Numbers
In order to find all the roots for the polynomial, we must use factor by grouping:
We will group the 4 terms into two binomials:
We then take the greatest common factor out of each binomial:
We can see now that each term has a common binomial as a factor:
In order to find the roots, we must set each factor equal to zero and solve:
Example Question #11 : Imaginary Numbers & Complex Functions
What are the imaginary root(s) of ?
Rewrite the expression as a positive root and the negative root
Take the square root of the positive root:
To check the answer, square the square root:
should be what was inside the square root in the beginning.
It checks out, so the complex root is
Example Question #12 : Imaginary Numbers & Complex Functions
Example Question #1 : Operations On Complex Numbers
Expand and Simplify:
Step 1: We will multiply the two complex conjugates: and
.
Step 2: Replace with
.
Simplify:
Step 3: Multiply the result of the complex conjugates to the other parentheses,.
The final answer after the product of all three binomials is
Example Question #1 : Operations On Complex Numbers
Expand: .
Quick Way:
Step 1: Expand .
.
Remember:
Step 2:
By this equivalence, I can just raise the answer of to the power
.
. Replace
..
Final answer:
Long Way:
Example Question #1 : Operations On Complex Numbers
Multiply:
Step 1: FOIL:
Recall, FOIL means to multiply the first terms in both binomials together, the outer terms together, the inner terms together, and finally, the last terms together.
Step 2: Simplify:
Step 3: Recall: . Replace and simplify.
Example Question #1 : Operations On Complex Numbers
When adding imaginary numbers, simply add the real parts and the imaginary parts.
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All GRE Subject Test: Math Resources
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