[MOVED] Given g(x)=2x^2+3, find [g(x+h)-g(x)]/h

Jade

Junior Member
Joined
Sep 16, 2006
Messages
95
g(x) = 2x^2 + 3

[g(x + h) - g(x)] / h

Would this be:

gx + gh - gx/h

or:

2x^2 + 3 + h - 2x^2 + 3/h

I am having problems computing the top??
 
g(x) = 2x<sup>2</sup> + 3
g(x+h) = 2(x+h)<sup>2</sup> + 3 = 2(x<sup>2</sup> + 2xh + h<sup>2</sup>) + 3 = 2x<sup>2</sup> + 4xh + 2h<sup>2</sup> + 3

now, you tell me ... what is [g(x+h) - g(x)]/h ???
 
I got it

I need to get into function mode - x+h takes the place of x

The answer would be 2x^2=4xh+2h^2+3/h
 
Jade said:
I need to get into function mode - x+h takes the place of x
So plug "x + h" (without your "minus" sign, above) in for "x" in the formula for "g(x)". Simplify.

From this, subtract the formula for "g(x)". Simplify.

Divide the result by h. Simplify.

There should not be any "equals" sign in your final expression.

Eliz.
 
Top