Explanation

• Parallel vectors pointing in the same direction have the same orientation.
• The angle between them is zero.
• Opposite parallel vectors have an angle of 180°.

Last verified on 14-11-2026

Explanation

The complex number i is located at (0, 1) on the Argand plane.

Its angle from the positive real axis is 90 degrees.

90 degrees is equal to π/2 radians.

Last verified on 14-11-2026

Explanation

The derivative of cos(x) is −sin(x).

The negative sign is an essential part of the rule.

This is a standard trigonometric differentiation formula.

Last verified on 14-11-2026

Explanation

• Two separate circles can have a maximum of four common tangents.
• If the circles touch externally, they have three common tangents.
• If the circles intersect, they have two common tangents.

Last verified on 14-11-2026

Explanation

A convergent sequence approaches a fixed finite value.

Its terms become very close to that limit.

A sequence that does not approach a finite limit is divergent.

Last verified on 13-11-2026