Indicies Flashcards
What is an index / indices
A number showing how many times a number is multiplied by itself.
How do you solve a number to the negative power e.g 7^-2
First multiply the number the amount of times the power shows
7×7 = 49
Then make it the reciprocal
So your answer is 1/49
How do you solve a number whose power is a fraction e.g 4^2/3
First you root the number by the denominator so
Cube root 4 =1.587
Next use the numerator as the power and raise it to the appropriate power
1.587^2 = 2.518
How do you solve a number with a negative fraction as its power
E.g 5^-1/2
First get the reciprocal of the number so
1/5^1/2
Then we use the denominator to root the number so
√1/5 = √5/5 = 0.4472
Now use the power to appropriately multiply the fraction
So 0.4472^1 = 0.4472
What happens when you multiply two numbers (of the same number) with a power
The powers add
8^4 × 8^2 = 8^6
What happens when you divide two numbers (of the same number) with a power
Subtract the powers
5^4 ÷ 5^2 = 5^2
Adding and subtracting with powers
The power doesn’t change but the number does - the powers must be the same
7^4 + 2^4 =9^4
What happens when you root a power
The power is divided by the root