Question

integrate integration cos (2 -7x)dx​

Answer 1

-1/7(Sin(2-7x)) that's a easy integration

Answer 2

Answer:

$- \dfrac{1}{7} \sin(2-7x) + c$

Step-by-step explanation:

Let

y = 2-7x

dy= -7dx

$\int\cos(2 - 7x) dx \\ = \int \cos(y) \dfrac{dy}{ - 7} \\ = - \dfrac{1}{7} \sin(y) + c$

using y = 2-7x here

$\dfrac{dy}{ dx} \\ = - \dfrac{1}{7} \sin(2-7x) + c$