## anonymous 4 years ago At x = 2, (dy)/(dx) =

1. UnkleRhaukus

what is the formula for y

2. anonymous

depends on what y(x) is ??

3. anonymous

here was the first part Let y= 6 x^5 - 9. Find A, B, and C so that (dy)/(dx) = Ax^B +C

4. anonymous

A = 30 B = 4. C =0

5. anonymous

use power rule dy/dx = 30x^4

6. UnkleRhaukus

$y(x)=6x^5-9$ ${dy(x) \over dx} =30x^4$ ${dy(2) \over dx} =30 \times 2^4=30 \times 16=480$

7. anonymous

thank you very much

8. anonymous

I was stuck

9. UnkleRhaukus

thinking about our answer to see if it makes sense, 480 is a big number , if that is our gradient at that point it is very steep but our equation for y is proportional to x^4 which gets large very quickly, so it makes sense that the slope is so steep