Question

differentiation of cos(ax+b)​

Answer 1

d/dx(cos(ax+b)

= - sin(ax+b)× d/dx(ax+b)

= - sin(ax+b)(a)

= - asin(ax+b)

Answer 2

$y = \cos(ax + c) \\ \\ \frac{dy}{dx} = \frac{d \cos(ax + c) }{dx} \\ \\ \frac{dy}{dx} = \frac{ \cos(ax + c) }{d(ax + c)}. \frac{d(ax + c)}{dx} \\ \\ \frac{dy}{dx} = - \sin(ax + c) \times a {(x)}^{0} + 0 \\ \\ = -a \sin(ax + c)$

Find by applying chain rule.

Hope this helps.