Let

f(x)=5 ·x2+2 ·x−3 and letx0= 1.

Theaverage rate of changeoffbetweenx= 1 andx= 1.18 equals ?

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- Sep 27th 2009, 09:05 AMsamtheman17average rate of change
Let

*f*(*x*)=5 ·*x*2+2 ·*x*−3 and let*x*0= 1.

The**average rate of change**of*f*between*x*= 1 and*x*= 1.18 equals ? - Sep 27th 2009, 09:16 AMProve It
I assume your function is

$\displaystyle f(x) = 5x^2 + 2x - 3$.

You have $\displaystyle f(1) = 5(1)^2 + 2(1) - 3$

$\displaystyle = 5 + 2 - 3$

$\displaystyle = 4$

Also $\displaystyle f(1.18) = 5(1.18)^2 + 2(1.18) - 3$

$\displaystyle = 6.962 + 2.36 - 3$

$\displaystyle = 6.322$.

The average rate of change will be given by

$\displaystyle \frac{f(1.18) - f(1)}{1.18 - 1}$

$\displaystyle = \frac{6.322 - 4}{0.18}$

$\displaystyle = \frac{2.322}{0.18}$

$\displaystyle = 12.9$. - Sep 27th 2009, 09:22 AMsamtheman17
ok, thank you so much!

that really helped :)

(ps.anwser is 12.9 as 1.18-1 is .18 not 1)