The correct answer for the question that is being presented above is this one: "(a)4." Suppose that during any period of 1/4 second there is one instant at which the crests or troughs of component waves are exactly in phase and maximum <span>reinforcement occurs, in 1 second, there will be 4 beats.</span>
Answer:
The function has a maximum in 
The maximum is:

Explanation:
Find the first derivative of the function for the inflection point, then equal to zero and solve for x




Now find the second derivative of the function and evaluate at x = 3.
If
the function has a maximum
If
the function has a minimum

Note that:

the function has a maximum in 
The maximum is:

Answer:
speed of puck acc. to the radar gun = 138 km/h
speed of player = 15 km/h
since the player is in motion when he shoots, the speed of the puck will be the sum of the speed of the player and the speed at which he shot. so,
speed of puck = speed of player + speed of puck acc. to player
138 = 15 + speed of puck acc. to player
speed of puck acc. to player = 138 -15
speed of puck acc. to player = 123 km/h
Brainly this answer if you think it deserves it
It will be traveling in the reverse direction it was originally going at 15.2 m/s