The height h (in feet) of an underhand volleyball serve can be modeled by h=−16t2+30t+4, where t is the time in seconds. After how many seconds is the ball 16 feet above the ground?

Step-by-step explanation:

We have been given that the height h (in feet) of an underhand volleyball serve can be modeled by , where t is the time in seconds.

To find the time when ball will be 16 feet above the ground, we will substitute in our given equation an solve for t as:

Using quadratic formula, we will get:

Therefore, the ball will be 16 feet above the ground after 0.58 seconds or 1.30 seconds.

7! = 7×6×5×4×3×2

3! = 3× 2

as 7! is multiple of 3! because 7! contains 3! that is 3× 2 as factor

so 7! /(3! ) = 7× 6× 5× 4

= 42 × 20

= 840

its b) 840✌✌✌

dhruv⭐