Answer:
A
Step-by-step explanation:
how long is the ball in the air ?
that is the same as asking : after how many seconds will the ball hit the ground (= reach the height of 0) ?
so, that means we need to find the zero solution of h(t).
at what t is h(t) = 0 ?
when at least one of the factors is 0 :
2(-2 - 4t)(2t - 5)
we have 3 factors
2 : can never be 0.
(-2 -4t) : can only be 0 for negative t, which does not make sense in our scenario (we cannot go back in time, only forward).
(2t - 5) : is 0 when 2t = 5 or t = 2.5
so, A is the right answer.
FYI : the starting height (on the hill) is given by t = 0 :
2(-2 - 0)(0 - 5) = 2×-2×-5 = 20 ft
The coefficient of these two number are -24 and 7. :)
Answer:
2(x + y)² - 9( x + y ) -5 = 0
⇒2(x + y)² - 10 (x+y) +1(x+y) -5 = 0
⇒2(x+y)(x + y - 5 ) + 1(x + y -5 ) = 0
taking (x + y -5 ) common ,
⇒(x + y -5 )[2(x + y) + 1] =0
⇒(x + y -5)(2x + 2y +1) =0
hope , you got this
Answer:
r = 7t
or not mathematically,
r(t) = 7t
r(t) means, r, which is a function of t.
Step-by-step explanation:
Initial size of the radius = 0 cm, at t = 0 s
Rate of increase of the radius of the circle = 7 cm/s
dr/dt = 7
dr = 7 dt
∫ dr = 7 ∫ dt
r = 7t + C (C is the constant of integration)
At t = 0, r = 0,
0 = 0 + C
C = 0
r = 7t.
r(t) = 7t
Answer:
10 inches
Step-by-step explanation:
