Mathematics
9 Online
smithm29:
Solving problems with linear systems
Join the QuestionCove community and study together with friends!
Sign Up
smithm29:
Vocaloid:
didn't we solve this yesterday? we got 25
smithm29:
yeah idk y they asked it again,,,
smithm29:
Vocaloid:
we also solved this yesterday
Join the QuestionCove community and study together with friends!
Sign Up
Vocaloid:
budget is less than/equal to 65,000
more expensive tree >= less expensive tree
Vocaloid:
*56,000
smithm29:
smithm29:
smithm29:
Join the QuestionCove community and study together with friends!
Sign Up
smithm29:
Vocaloid:
when you see (x+h) in the transformation, you get shifted left h units
so f(x+2) is the graph of x^2 shifted left 2 units
smithm29:
smithm29:
do u need to see the graphs?
Vocaloid:
not really,
again, since we have f(x+1) we shift the graph of f(x) = x^3 to the left 1 unit
Join the QuestionCove community and study together with friends!
Sign Up
smithm29:
smithm29:
would we go to the left 3?
Vocaloid:
yes
smithm29:
Vocaloid:
if you see f(x-h) it gets moved to the right h units
so f(x-4) is f(x) moved to the right 4 units
Join the QuestionCove community and study together with friends!
Sign Up
smithm29:
Vocaloid:
the +2 is outside the parentheses so we move the function up 2 units
smithm29:
Vocaloid:
the -5 is outside the parentheses so we move down 5 units
smithm29:
Join the QuestionCove community and study together with friends!
Sign Up
Vocaloid:
the (1/4) is inside the parentheses so the function gets "squished" (let me try sketching)
Vocaloid:
|dw:1501514700652:dw|
Vocaloid:
|dw:1501514729361:dw|
smithm29:
Vocaloid:
same thing, the function gets "flatter"
Join the QuestionCove community and study together with friends!
Sign Up
Vocaloid:
|dw:1501514834432:dw|
smithm29:
Vocaloid:
function gets "stretched" so the slope becomes steeper
Vocaloid:
|dw:1501514894133:dw|
smithm29:
Join the QuestionCove community and study together with friends!
Sign Up
Vocaloid:
since the stretch factor is less than 1 the graph becomes less steep
smithm29:
Vocaloid:
stretch factor is >1 so graph becomes steeper
smithm29:
Vocaloid:
does it show you the graph of f(x)?
Join the QuestionCove community and study together with friends!
Sign Up
smithm29:
no not this one
Vocaloid:
since it gets shifted to the right 1 unit I guess I would add 1 to the x-value to get (2,5)? hm.
smithm29:
Vocaloid:
add 4 to the x-value to get (2,-1)
smithm29:
Join the QuestionCove community and study together with friends!
Sign Up
Vocaloid:
subtract 2 from the x-coordinate
smithm29:
so (0,9)?
Vocaloid:
good
smithm29:
Vocaloid:
add 4 to the y-coordinate
Join the QuestionCove community and study together with friends!
Sign Up
smithm29:
5,8?
Vocaloid:
good
smithm29:
Vocaloid:
subtract 4 from the y-coordinate
smithm29:
2,-1
Join the QuestionCove community and study together with friends!
Sign Up
Vocaloid:
good
smithm29:
Vocaloid:
hm. I ~believe~ you would multiply the x-coordinate by (3/4)
smithm29:
so -4 1/2,-5
Vocaloid:
I think so :S
Join the QuestionCove community and study together with friends!
Sign Up
smithm29:
Vocaloid:
multiply x-coordinate by (-2/3)
smithm29:
Vocaloid:
ok so the little circle thing means we put f(x) as x into equation g(x)
Vocaloid:
g(x) = x^2 = (-x-2)^2
if x = - 6, then (-x-2)^2 = ?
Join the QuestionCove community and study together with friends!
Sign Up
smithm29:
40?
Vocaloid:
do the parentheses first
if x = -6, then -x - 2 = ?
smithm29:
4?
Vocaloid:
good, and 4^2 = ?
smithm29:
16
Join the QuestionCove community and study together with friends!
Sign Up
Vocaloid:
good so 16 = your ans
smithm29:
Vocaloid:
similar as before
f(x) = 2x + 6
g(x) = x^3
g(x) dot f(x) = (2x+6)^3, and if x = 0, then this equals...?
smithm29:
216?
Vocaloid:
again, parentheses first
if x = 0, 2x + 6 = ?
Join the QuestionCove community and study together with friends!
Sign Up
smithm29:
6
smithm29:
?
Vocaloid:
good
and 6^3 = ?
smithm29:
216
Vocaloid:
oh you were right the first time, it's 216 >>
Join the QuestionCove community and study together with friends!
Sign Up
Vocaloid:
as your answer
smithm29:
Vocaloid:
same thing
g dot f(x) = (7x+8)^4
x = 0
ans = ?
smithm29:
4096?
Vocaloid:
good
Join the QuestionCove community and study together with friends!
Sign Up
smithm29:
Vocaloid:
f(x) = -x+ 7
g(x) = square root(x-3)
f dot g(x) = -square root(x-3) + 7
x = 4
ans = ?
smithm29:
-9.6?
Vocaloid:
not quite
start with the parentheses
if x = 4, then x - 3 = 1
square root of 1 = 1
-square root of 1 = -1
(- square root of 1) + 7 = 6 = your answer
smithm29:
Join the QuestionCove community and study together with friends!
Sign Up
Vocaloid:
if g(x) = sqare root(x+1) and x = 24, what is g(x)?
smithm29:
um... idk
smithm29:
how do i square root x?
Vocaloid:
start with the parentheses first
if x = 24, then x + 1 = 25
what's the square root of 25?
smithm29:
5
Join the QuestionCove community and study together with friends!
Sign Up
smithm29:
so the answer would be 5?
Vocaloid:
not yet
Vocaloid:
now we plug that into f(x)
if x = 5, then f(x) = -9x + 9 = ?
smithm29:
so -36 is the answer?
Vocaloid:
good, yes
Join the QuestionCove community and study together with friends!
Sign Up
smithm29:
Vocaloid:
same thing as before
x = 7
g(x) = square root(x-6)
g(x) = ?
smithm29:
1
Vocaloid:
good, now we re-substitute back into f(x)
x = 1
f(x) = -5x - 1 = ?
smithm29:
-6
Join the QuestionCove community and study together with friends!
Sign Up
Vocaloid:
good, that's your ans
smithm29:
Vocaloid:
f dot g = (-9x+3)^4 = ans
Vocaloid:
can we open a new question after this
smithm29:
yeah
Join the QuestionCove community and study together with friends!
Sign Up
smithm29:
is -6554 right?
Vocaloid:
no, it's asking for a function, not a number
Vocaloid:
(-9x+3)^4 = answer
smithm29:
oh lol