Cho hàm số \(f\left( x \right) = 1 - \frac{1}{{{{\cos }^2}x}}\). Khẳng định nào dưới đây đúng?

A. F(x) = sinx + cosx + C;

B. F(x) = sinx – cosx + C;

C. F(x) = −sinx + cosx + C;

D. F(x) = −sinx – cosx + C.

A. \(\int {f\left( x \right)dx} = x - \cos x + C\);

B. \(\int {f\left( x \right)dx} = x + \sin x + C\);

C. \(\int {f\left( x \right)dx} = x + \cos x + C\);

D. \(\int {f\left( x \right)dx} = \cos x + C\).

A. \(\int {\left( {2\sin x + 3x} \right)dx} = - 2\cos x + \frac{3}{2}{x^2} + C\);

B. \(\int {\left( {2\sin x + 3x} \right)dx} = 2\cos x + 3{x^2} + C\);

C. \(\int {\left( {2\sin x + 3x} \right)dx} = {\sin ^2}x + \frac{3}{2}x + C\);

D. \(\int {\left( {2\sin x + 3x} \right)dx} = \sin 2x + \frac{3}{2}{x^2} + C\).

A. sinx + 3x² + C;

B. −sinx + 3x² + C;

C. sinx + 6x² + C;

D. −sinx + C.

A. \(\int {\cos \frac{x}{2}\sin \frac{x}{2}dx} = \frac{1}{2}\sin x + C\);

B. \(\int {\cos \frac{x}{2}\sin \frac{x}{2}dx} = \frac{1}{2}\cos x + C\);

C. \(\int {\cos \frac{x}{2}\sin \frac{x}{2}dx} = - \frac{1}{2}\sin x + C\);

D. \(\int {\cos \frac{x}{2}\sin \frac{x}{2}dx} = - \frac{1}{2}\cos x + C\).

A. \(\int {f\left( x \right)dx} = 2\sin \left[ {2\left( {x + \pi } \right)} \right] - {x^3} + C\);

B. \(\int {f\left( x \right)dx} = \sin 2x - {x^3} + C\);

C. \(\int {f\left( x \right)dx} = - \sin \left[ {2\left( {x + \pi } \right)} \right] - {x^3} + C\);

D. \(\int {f\left( x \right)dx} = - 4\sin \left[ {2\left( {x + \pi } \right)} \right] - 6x + C\).

A. lnx – cosx + C;

B. \( - \frac{1}{{{x^2}}} - \cos x + C\);

C. ln|x| + cosx + C;

D. ln|x| − cosx + C.