1. ## Differentiation

Hey guys could you just check if i did this right please?

q: Differentiate using the chain rule

a:
$\displaystyle y(x) = cos(5x^2+8)$

$\displaystyle u = (5x^2+8)$

$\displaystyle du/dx = 10x$

$\displaystyle dy/du = -sin(u)$

$\displaystyle dy/dx = -sin(10x)$

Hey guys could you just check if i did this right please?

q: Differentiate using the chain rule

a:
$\displaystyle y(x) = cos(5x^2+8)$

$\displaystyle u = (5x^2+8)$

$\displaystyle du/dx = 10x$

$\displaystyle dy/du = -sin(u)$

$\displaystyle dy/dx = -sin(10x)$
$\displaystyle \frac{dy}{dx}=\frac{dy}{du}\frac{du}{dx}=[-sin(5x^2+8)][10x]$

RonL

Hey guys could you just check if i did this right please?

q: Differentiate using the chain rule

a:
$\displaystyle y(x) = cos(5x^2+8)$

$\displaystyle u = (5x^2+8)$

$\displaystyle du/dx = 10x$

$\displaystyle dy/du = -sin(u)$

$\displaystyle dy/dx = -sin(10x)$
Hello,

$\displaystyle dy/du = -sin(u)$ here you have to re-substitute:
$\displaystyle dy/dx = -sin(5x^2+8) \cdot (10x)$

thanks guys