Answer:
Step-by-step explanation:
2x+6
<3
Callie
Given f(x)=3x²-5x-2
a) To find f(a+h) replace x with a+h in the given function. So,
f(a+h)=3(a+h)²-5(a+h)-2
=3(a²+2ah+h²)-5(a+h)-2 By using the formula (x+y)²=x²+2xy+y².
=3a²+6ah+3h²-5a-5h-2 By distributing property.
b) Similarly to find f(a) we need to replace x with a. So,
f(a)=3a²-5a-2
So, f(a+h)-f(h)= (3a²+6ah+3h²-5a-5h-2)-(3a²-5a-2)
=3a²+6ah+3h²-5a-5h-2-3a²+5a+2.
=6ah+3h^2-5h (All other terms has been cancel out)
Answer:
1.5 mph
Step-by-step explanation:
Let speed of boat be x
let speed of current be c
Also, note D = RT
D is distance
R is rate
T is time
Now, for first leg, we can write:
(x+c)3 = D
And for second leg , we can write:
(x-c)4.8 = D [note 4 hour 48 minutes is 4.8 hours]
We can equate both D's to get:
(x+c)3 = (x-c)4.8
3x + 3c = 4.8x - 4.8c
7.8c = 1.8x
We know x = 6.5 [given], plugging it in and solving for c:
7.8c = 1.8(6.5)
c = 1.5
Speed of Current = 1.5 miles per hour
