Question

Simplify:
1. square root of 80
2. square root of 72
3. square root of 12

Answer 1

\[\sqrt{ab} = \sqrt{a}\sqrt{b}\]

eg 1. \[\sqrt{80} = \sqrt{16}\sqrt{5} = 4\sqrt{5}\]

Answer 2

so square root of 72 = square root 12 * square root 6, so IM LOST

Answer 3

try to get square numbers out of it :) dont worry nearly everyone struggles with it at first

Answer 4

72 = 4 * 18

Answer 5

thats a good one because 4 is a square number

Answer 6

so 2 square root 18?

Answer 7

yep, can you take out another square number from 18?

Answer 8

No?

Answer 9

name some square numbers :D

Answer 10

see if any go into 18

Answer 11

My only answers i have is:
6SR2
3SR2
2SR3
0
6

i dont have 4SR18

Answer 12

2SR18, my bad.

Answer 13

18 is 2 * 9 isnt it?

Answer 14

and 9 is a square number

Answer 15

yeah. so 3*3 =9
so 2SR3?

Answer 16

well before we had 2SR18

2sqrt(18) = 2sqrt(9)sqrt(2)

Answer 17

= 2*3*sqrt(2)

Answer 18

= 6sqrt(2)

Answer 19

you see?

Answer 20

Oh. Ok. That makes since. (:

Answer 21

So with SR of 12...

Answer 22

have a go with sqrt(12) , its a bit easier

Answer 23

2*6
3*4

Answer 24

which one of those has a square number?

Answer 25

3*4?

Answer 26

yep!

Answer 27

SR 4= 2

Answer 28

ok, so sqrt(12) = sqrt(4)sqrt(3) = ?

Answer 29

2SR3?

Answer 30

yeah! i think you've got it

if you're still unsure how about trying to simplify
sqrt(20)

Answer 31

My only answer choices are:
3
6
2SR29
SR6
4SR2

Answer 32

what for 12?

Answer 33

yeah.

Answer 34

its none of those...

Answer 35

I have to find the distance between the coordinates:
(7,3) and (7,-3) & i got SR12

Answer 36

oh, nevermind. i added wrong. Its SR of 36 for the answer. & SR of 36 = 6 :)

Answer 37

ah i see why you want these now :)

Answer 38

huh? lol

Answer 39

i thought this was just the question, i didnt realise you were finding distances

Answer 40

Oh, nuhuh. lol

Answer 41

Can you help me with something else?

Answer 42

yeah sure

Answer 43

im here to help :)

Answer 44

Determine the length of the major and minor axes of the following ellipses:
1. x^2/16+y^2/9=1

Answer 45

i havent done ellipses in aaages lol

gimme a sec

Answer 46

lol. ok.

Answer 47

ok, so this ellipse has centre (0,0) doesnt it?

Answer 48

Im not sure, I just started learning it.

Answer 49

ok, i could do a quick run through on ellipses, that way it'll refresh my memory xD

Answer 50

Thank you so much.

Answer 51

ok, since you are doing ellipses you have probably seen circle equations before? , of the form
\[x^2 + y^2 = r^2\]

Answer 52

where r is the radius

Answer 53

yeah.

Answer 54

lets think about the circle with equation
\[x^2 + y^2 = 1\] it looks like this: (radius is 1)
now we're going to stretch it by scale factor 4 in the x - direction

so in the equation we replace x by (x/4)

\[(\frac{x}{4})^2 + y^2 = 1\]or\[\frac{x^2}{16} + y^2 = 1\]

the new graph looks like this: