Question

Determine the sign of cos pi divided by seven

Answer 1

The sign of cos pi divided by seven is positive

Solution:

Given that we have to determine the sign of cos pi divided by seven

Let us first understand the signs of sine, cosine and tangent by quadrants

In the first quadrant, the values for sin, cos and tan are positive.

In the second quadrant, the values for sin are positive only.

In the third quadrant, the values for tan are positive only.

In the fourth quadrant, the values for cos are positive only.

Determine the sign of cos pi divided by seven

cos pi divided by seven ⇒ $cos \frac{\pi}{7}$

The angle $\cos \frac{\pi}{7}$ lies in quadrant 1, Where angles are zero (0) to $\frac{\pi}{2}$

In first quadrant, all trignometric functions are positive

so, $\cos \frac{\pi}{7}$ has positive sign.