1.

1). sin2x > \(\frac{1}{2}\) and cos2x> \(\frac{1}{2}\)2). sin2x > \(\frac{1}{2}\) and cos2x < \(\frac{1}{2}\)3). sin2x < \(\frac{1}{2}\) and cos2x < \(\frac{1}{2}\)4). sin2x, cos2x at least one is less than 1

Answer»

If 0 ≤ X ≤ $(\frac{{\rm{\PI }}}{2})$

Then 0 ≤ sinx ≤ 1

0 ≤ cosx ≤ 1

∴ (IV) is ALWAYS right

sinx increases from 0° to 90° in first QUADRANT and cosx decreases.



Discussion

No Comment Found