(f+g-k)(x) means to add the equations f(x) and g(x) then subtract k(x)
2x^2 + 3x + 4x - 9 = 2x^2 +7x -9
2x^2 + 7x - 9 - x^2 -7x = x^2 -9
The answer is : x^2 - 9
Answer:
(a) 
(b) 
Step-by-step explanation:
(a)
can also be written as
x 
the
= ± y
Therefore :
= ±
since it was given that y < 0 , then the factor will be 
(b)
can also be written as :
x 
Therefore , one of the factor is 
Answer:
90.5
Step-by-step explanation:
Velocity is a time-derivative of displacement or the height, in this case.


At maximum height, the velocity is 0 and the height is 128.
Substitute these values into both equations above,


From the first equation,

Substitute for
.





When waves travel from one medium to another the frequency never changes. As waves travel into the denser medium, they slow down and wavelength decreases. Part of the wave travels faster for longer causing the wave to turn. The wave is slower but the wavelength is shorter meaning frequency remains the same