Wednesday, October 28, 2009

GMAT/CAT PREPARATION EMAIL COURSE DAY 13


You must be having a good understanding of concepts of surds and indices to solve the problems faster in CAT ..


http://catdumps.blogspot.com/2009/03/cat-gmat-gre-mba-index-if-m-is-positive.html

Here are the Laws of SURDS AND INDICES


http://catdumps.blogspot.com/2009/03/laws-of-surds-and-indices.html


Multiplying and Dividing


To multiply powers with the same base, keep the same base and add the exponents

3 5 3+5 8
b X b = b = b


To divide powers with the same base, keep the same base and subtract the exponents

10 8 10-8 2
b / b = b = b



Raised Powers to Powers


To raise a power to a power, multiply the exponents:

3 5 3x5 15
(b ) = b = b



Negative Powers


A number raised to a negative exponent is simply the reciprocal of that number raised to the corresponding positive exponent.

-3
2 = 1 / 2^3 = 1 /8


Simplifying Roots


To simplify a square root, factor out the perfect squares under the radical, remove the perfect squares and put the result in front:
__ ____ __ __ __
V20 = V4X5 = V4 X V5 = 2 V5



Adding and Subtracting Roots


You can add or subtract radical expressions when the part under the radicals is the same
__ __ __
2 V6 + 3 V6 = 5 V6


Don't try to add or subtract when the radicals are different.
You cannot simplify expressions like:
___ __ ___ ___
2 V 5 + 3 V 6 {is not equal to 5V 6 or 5V 6 }



Multiplying and Dividing Roots


The product of square roots is equal to the square root of the product:
__ __ ______ __
V 5 x V3 = V5 X 3 = V15


The quotient of square roots is equal to the square root of the quotient:

__ __ ____ ___
V8 /V2 = V8/2 = V 4 =2