Integral of tan^4 x or cot^4 x using tan^2 x = sec^2 x - 1

1. A.
   $\frac{7}{3}$
2. B.
   $\frac{5}{3}$
3. C.
   $\frac{4}{3}$
4. D.
   $\frac{1}{3}$

Tap an option to check your answer.

1. A.
   $\dfrac{\cot^3 x}{3} - \cot x + x + c$
2. B.
   $\dfrac{\cot^3 x}{3} + \cot x + x + c$
3. C.
   $-\dfrac{\cot^3 x}{3} + \cot x + x + c$
4. D.
   $\dfrac{\cot^3 x}{3} - 2\cot x + x + c$

Tap an option to check your answer.