Category: Math 11

This week we did the review and skill check for the test

The important thing that we learned was discriminant:

There are one solution(2 equal solutions)

There are two distinct(unequal)solutions

$latex b^2-4ac<0$

There are no roots.

look the picture

use the way that we learned to make ax²+bx+c=0 change  to

Ex:

x^2+9x -2=0

use the formula that we just make

a=1，b=9，c=-2

finished

so we can use this formula to solve the question easily and correctly

When you simplify your radicals down, you can only add common radicals together. When you’re adding or subtracting radicals, the radicand always stays the same, which is why you need to have a common radicand. Once you’ve collected common radicals you you either add or subtract the co-efficients together depending on the sign

EX:3√5+6√5（They have same radicand）=9√5

We also learned how to make it simplify

You have to simplify the number in the  root as much as you can by multiplying it by several equal numbers

EX:square root：√64=√4*4*4=4√4

cube root： ³ √81=³√3*3*3*3=3 ³√3

it makes you can better to add up some numbers with the root

see the picture

√25=5

The absolute value of a real number is defined as the principal square root(√25) of the square of a number.

EX:|9|=3 ,|-9|=3

√9²=√81=9=|9|=|-9|

√（-9）²=√81=9=|9|=|-9|

Simplifying Radical Expressions

Coefficient√Radicand

Square roots :ex ²√16=4

Roots(-other roots)[

Cube roots :ex³√27=3

Warn：²√x     （x≥0）restriction

³√x     （x∈R）restriction