Complete question :
a ladder 5 meters long is leaning against a wall. the base of the ladder is sliding away from the wall at a rate of 1 meter per second. how fast is the top of the ladder sliding down the wall at the instant when the base is 4 meters from the wall?
Answer:
-4/3 m/s
Step-by-step explanation:
Using Pythagoras :
a² = x² + c²
5² = x² + y² - - - (1)
The horizontal distance x with respect to time t = 1m/sec
dx/dt = 1m/sec
To obtain the vertical height 'y' with respect to time t when x = 4
5² = x² + y²
Wen x = 4
5² = 4² + y²
25 = 16 + y²
y =√(25 - 16)
y = 3
Differentiate (1) with respect to t
x² + y² = 25 - ---- - (1)
2x * dx /dt + 2y dy/dt = 0
dx/dt = 1
x = 4.
y = 3
2(4)(1) + 2(3) * dy/dt = 0
8 + 6dy/dt = 0
6 dy/dt = - 8
dy/dt = - 8/6
dy/dt = - 4/3
Hi, the area of a rectangle is: A = L * W.
Question 1:
Area of surface of the swimming pool is: 1000 * 100, or 100,000 square feet.
Question 2:
Volume of a rectangular box is: V = L * W * H.
Volume of the swimming pool is: V = 1000 * 100 * 10, or 1,000,000 cubic feet.
Question 3:
Question 1 in powers of 10 is: 105
Question 2 in powers of 10 is: 106
Factor the following:
x^2 - 36
x^2 - 36 = x^2 - 6^2:
x^2 - 6^2
Factor the difference of two squares. x^2 - 6^2 = (x - 6) (x + 6):
Answer: (x - 6) (x + 6)
Answer:
Step-by-step explanation:
In a G.P, the nth term is given as
Un=ar^(n-1)
Where
a is first term
n is nth term
And r is common ratio
So in the question given above,
The third term exceed the first term by 16
i.e U3=U1+16
Where U1=a. First term
U3=a+16
Given also that, the sum if the third term and fourth term is 72.
Then U3+U4=72.
We are told to find common ratio (r)
U3=ar^3-1
U3=ar^2
Also, U4=ar^3
U3+U4=72
ar^2+ar^3=72
ar^2(1+r)=72. equation 1
Also for
U3=a+16
ar^2=a+16
ar^2-a=16
a(r^2-1)=16. From (x^2-y^2)=(x+y)(x-y)
Then,
a(r-1)(r+1)=16. Equation 2
Divide equation 2 by equation 1
a(r-1)(r+1)/ar^2(1+r) =16/72
Then a cancel a and (1+r) cancel (1+r)
So,
(r-1)/r^2=2/9
Cross multiply
9(r-1)=2r^2
2r^2-9r+9=0
Solving the quadratic equation
2r^2-6r-3r+9=0
2r(r-3)-3(r-3)=0
(r-3)(2r-3)=0
r-3=0. Or. 2r-3= 0
Then r=3 or r=3/2
17 percent of 24320 is 4134.4
basically minus that
so
24320 - 4134.4 = 20,185.60
