Question

Can someone please help me....


1. Given f(x) = x2 + 2x, find f(a – 3)

2. If f(x0=x/x-3 and g(x)=2x-1, find (f-g)(x)

Answer 1

1). f(x) = x^2 + 2x, to find f(a – 3) it means
f(a-3) = (a-3)^2 + 2(a-3) = ....

Answer 2

ok thanks,

Answer 3

can u retype f(x) = ...? for the 2nd

Answer 4

Yea sorry...

If (x)=x/x-3 and g(x)=2x-1, find (f-g)(x)

Answer 5

it similar by f(x) - g(x) = x/x-3 - (2x-1) = ... simplify again :)

Answer 6

can you help me with a few more questions??

Answer 7

sure if i can i will help u

Answer 8

If f(x)=x^2+1 and g(x)=1/x, find [f*g](x)

Which equation best represents a line perpendicular to the graph of x+3y=9?

Answer 9

f*g = (x^2+1)*1/x = x^2/x + 1/x = ...
the line ax+by=c will perpendicular with the line bx-ay=k

Answer 10

thank you!!!

Answer 11

very welcome :)

Answer 12

I just have one more question @RadEn ...for problems like this how do I work it out to get the correct answer?

Write the standard form of an equation of the line parallel to the graph of x-2y-6=0 and passing through A(-3,2)

Answer 13

nice way :
actually i will copy and paste x-2y=(...)-2(...)
bla bla is the coordinat given, what u get

Answer 14

so you mean... is would be x-2y=(-3)-2(2) ?

Answer 15

I don't get it...sorry

Answer 16

that's right, just calculate for the right side then simplify

Answer 17

oh ok...thanks so much. your a life saver!!!(:

Answer 18

nopes... math is fun right :)

Answer 19

not really...I'm kinda failing precal :/ I just don't get it...

Answer 20

Find the value of k such that -2/3 is a zero of the function f(x)=4x+k/7

Find the zero of f(x)=-2/3x-12

Line k pass through A(-3,-5) and has a slope of -1/3. What is the standard form of the equation for line k?

@RadEn could you help with these three...I'm really stuck :/ I tried working them out and I turned them in and got them wrong...I just want to understand how to do this..

Answer 21

-2/3 is a zero of the function f(x)=4x+k/7, it means
4(-2/3) + k/7 = 0
now, solve for k

Answer 22

-2.66+k/7
18.5=k? I don't know...

Answer 23

4(-2/3) + k/7 = 0
-8/3 + k/7 = 0
move -8/3 to right side, be
k/7 = 0+8/3
k/7 = 8/3
multiply by 7 to both sides gives
7 * k/7 = 7 * 8/3
k = 56/3

Answer 24

Oh ok..I get it...what about the other ones?

Answer 25

To find the zero of f(x)=-2/3x-12, set f(x) = 0, so
-2/3 x - 12 = 0
solve for x (do like above)

Answer 26

-12=0+(-2,3)
-12=-2/3
12=-2/3*-12
=18

Answer 27

I'm not sure....

Answer 28

unlucky :)
-2/3 x - 12 = 0
move -12 to right side :
-2/3 x = 12
multiply by -3/2 to both sides :
-3/2 * -2/3 x = -3/2 * 12
x = -18

Answer 29

oh ok...thanks again!!!

Answer 30

ok, for the last one...
the standard form of the equation for straight line is
y=mx+c, with m is slope
from information above, Line k pass through A(-3,-5) and has a slope of -1/3
so, -5 = -1/3 (-3) + c
solve for c

Answer 31

so...3y=x-18

thats the old answer I had and got wrong..

Answer 32

u must get c, first
then u will get the answer

Answer 33

-6??

Answer 34

ok, right... c=-6
therefore the line of k is
y=mx+c
y=-1/3 x - 6

Answer 35

ok..what the next step?

Answer 36

its finished

Answer 37

oh ok then,...thanks again fore everything!!