Answer:
Step-by-step explanation:
Given function l:
h= -16t² + 26t
where h represents height and t represents time.
The time for dolphin atbthe height 5 feet is given by putting the value of h as 5 in the function,
5 = -16t² + 26t
16t² - 26t + 5 = 0
For this equation: a=16, b=-26, c=5
Use quadratic formula with a=16, b=-26, c=5.
x=(−b±√b2−4ac)/2a
x=−(−26)±√(−26)2−4(16)(5)/2(16)
x=13/16 + 1/16√89 or x=13/16+ −1/16√89
x=1.40 or 0.22
Yes you are correct. You take half of the x coefficient 18 to get 9, then you square 9 to get 81
x^2+18x+81 is a perfect square trinomial which factors to (x+9)^2
Is there like a pic for it
D is also correct. if you need an explanation let me know