Where sin^4 x + cos^4 x is increasing

1. A.
   $0<x<\frac{\pi}{8}$
2. B.
   $\frac{\pi}{4}<x<\frac{\pi}{2}$
3. C.
   $\frac{3\pi}{8}<x<\frac{5\pi}{8}$
4. D.
   $\frac{5\pi}{8}<x<\frac{3\pi}{4}$

Tap an option to check your answer.

1. A.
   $\ 0 < x < \frac{\pi}{8}$
2. B.
   $\frac{\pi}{4} < x < \frac{\pi}{2}$
3. C.
   $\frac{3\pi}{8} < x < \frac{5\pi}{8}$
4. D.
   $\frac{5\pi}{8} < x < \frac{3\pi}{4}$

Tap an option to check your answer.

1. A.
   $0 < x < \dfrac{\pi}{8}$
2. B.
   $\dfrac{\pi}{4} < x < \dfrac{\pi}{2}$
3. C.
   $\dfrac{\pi}{2} < x < \dfrac{5\pi}{8}$
4. D.
   $\dfrac{5\pi}{8} < x < \dfrac{3\pi}{4}$

Tap an option to check your answer.