Question

If $\int \sin xdx$ $=-\cos x+c_1$ , then $\int 2\sin xdx$ is equal to

• A. $\cos x+c_1$
• B. $-2\cos x+c_1$
• C. $2\cos x+c_1$
• D. $-\cos x+c_1$

Answer 1

The correct option is B $-2\cos x+c_1$

Given :- $\int \sin xdx=-\cos x+c_1$

Now as we can see that the required integration $2$ times the given integration.

Hence we get:

$\int 2\sin xdx=-2\cos x+c_1$

But as we know that $c_1$ is a constant, so any other multiple of it will also be a constant, hence we get option B as the correct answer.