Roots and Exponent Flashcards
Square root -> never a negative number
sqrt(100)= 10 and never -10
sqrt(-16)
not a real number
-> we can’t find the real number with negative sqrt unlike positive
cuberoot(-64)
can be a real number (-4-4-4)
-> we can find positive number for negative cubic root
nsqrt(x^n)
|x| -> always positive
Square root of a whole number
whole number
Square root of non-perfect square
not a whole number
1st 11 cubic roots
1) 0^3= 0
2) 1^3=1
3) 2^3= 8
4) 3^3= 27
5) 4^3= 64
6) 5^3= 125
7) 6^3= 216
8) 7^3= 343
9) 8^3= 512
10) 9^3= 729
11) 10^3= 1000
cubicroot(-8)
-2-2-2= -8
When simplying radicals with square roots
simplify any perfect square and cubes
Approximate square roots
try to find the root that is inbetween and estimate it
cuberoot(2)
1.3
cuberoot(3)
1.4
cuberoot(4)
1.6
cuberoot(5)
1.7
cuberoot(6)
1.8
cuberoot(7)
1.9
cuberoot(8)
2
cuberoot(9)
2.1
fourthroot(2)
1.2
fourthroot(3)
1.3
fourthroot(4)
1.4
fourthroot(5)
1.5
fourthroot(6)
1.6
fourthroot(7)
1.6
fourthroot(8)
1.7
fourthroot(9)
1.7
sqrt(5)*sqrt(7) can be written as
sqrt(5*7)
-> to multiply them need to have same root
cubic(25)*cubic(5) can be expressed as
cubic(25*5)
If they don’t have the same root, can you combine them?
No you can’t
-> sqrt(100)*cubic(27)-> you can’t just multiply 100 and 27 n
Dividing radicals can be combined
- > sqrt(54)/sqrt(6)= sqrt(54/6)
- > cubic(24)/cubic(3)= cubic(24/3)