Breaking News
Home / Maths / SIMPLE INTEREST & COMPOUND INTEREST & SURDS & INDICES

SIMPLE INTEREST & COMPOUND INTEREST & SURDS & INDICES

SIMPLE INTEREST & COMPOUND INTEREST & SURDS & INDICES

Simple Interest

The formula for calculating simple interest is:

Simple Interest = (Principal x Interest Rate x Time)/100

= (P x R X T)/100

Compound Interest

The formula for calculating compound interest is:

Compound Interest = Total amount of Principal (P) and Interest in future (or Future Value,”I”) less Principal amount at present (or Present Value)

=    [P (1 + I) T] – P

=    P [(1 + I) T – 1]

Where P = Principal, I = annual interest rate in percentage terms, and

T = number of compounding periods.

 

Surds

When we can’t simplify a number to remove a square root (or cube root etc) then it is a surd.

Example: √2 (square root of 2) can’t be simplified further so it is a surd

Example: √4 (square root of 4) can be simplified (to 2), so it is not a surd!

INDICES

We recall that a power is the product of a certain number of factors, all of which are the same. For example, 37 is a power, in which the number 3 is called the base and the number 7 is called the index or exponent.

In the module, Multiples, Factors and Powers, the following index laws were established for positive integer exponents. So positive integers and , and rational numbers and , we have:

  • To multiply powers with the same base, add the indices.
    amanam+n
  • To divide powers with the same base, subtract the indices.
    a− n, (provided m > n.)
  • To raise a power to a power, multiply the indices.
    (am)namn
  • A power of a product is the product of the powers.
    (ab)mambm
  • A power of a quotient is the quotient of the powers.
    SIMPLE INTEREST & COMPUND INTEREST & SURDS & INDICES (provided b≠ 0.)