Feedback refers to the response given by the receiver of a message to the sender. It is a critical component of the communication process as it ensures that the message has been understood as intended.
Importance:
1. Clarity: Feedback helps clarify any doubts or misunderstandings, making the communication process more effective.
2. Improvement: It allows the sender to refine their message or approach based on the receiver's response.
3. Encouragement: Positive feedback boosts the sender’s confidence and encourages better communication.
In summary, feedback is a two-way process that facilitates better understanding and connection between the sender and receiver.
Assertion (A): The sum of the first fifteen terms of the AP $21, 18, 15, 12, \dots$ is zero.
Reason (R): The sum of the first $n$ terms of an AP with first term $a$ and common difference $d$ is given by: $S_n = \frac{n}{2} \left[ a + (n - 1) d \right].$