Question

1. Find the difference quotient for f(x) = 4x^2 - 2x
2. Let f(x)= x^2 - 25 and g(x) = x + 5. Find and simplify
a. (f - g)(x)
b. (f/g)(x)

Answer 1

f(x+h)-f(x)
-----------
h

Answer 2

@ odehye can u start it

Answer 3

Thanks Mark

Answer 4

I'm starting

Answer 5

f(x) = 4x^2 - 2x

f(x+h) = 4(x+h)^2 - 2(x+h)

f(x+h) = 4(x^2+2xh+h^2) - 2(x+h)

f(x+h) = 4x^2+8xh+4h^2 - 2x-2h

Answer 6

@mark_o This is where i'm stuck

Answer 7

f(x+h) = 4x^2+8xh+4h^2 - 2x-2h
next here is
f(x+h)- f(x)= 4x^2+8xh+4h^2 - 2x-2h -(4x^2 - 2x)
f(x+h)- f(x)= 8xh + 4h^2 -2h correct ? now divide this to h to make

f(x+h)- f(x)
----------- =?
h

Answer 8

= 8xh + 4h^2 -2h
______________________________
h

=2h(4x + 2h^2 -2h)
_____________________
h


=8x + 2h^2

Answer 9

@mark_o. will this be right?

Answer 10

2h^2/h= 2h and 2h/h =2 therefore

=?

Answer 11

diff Quotient=8x +4h-2

Answer 12

2). Let f(x)= x^2 - 25 and g(x) = x + 5

a. (f - g)(x)=f(x)-g(x)= (x^2 - 25) - ( x + 5) =?

b) (f/g)(x)= f(x)/g(x)=(x^2 - 25)/( x + 5) =? hint try to factor the numerator then they cancel out

Answer 13

a. (f - g)(x)=f(x)-g(x)= x^2 - 25 - x - 5 =?
is it=x^2 -x - 30 ? ...yes or no

b) (f/g)(x)= f(x)/g(x)=(x^2 - 25)/( x + 5)
=(x +5)(x-5)/( x + 5) =?
is it = x-5 ? ....yes or no...

Answer 14

a. Yes
b. yes

I like the way you make it simple to understand. Thanks a lot.