Help pleaseeeee I can’t do this and don’t guess don’t do it if you don’t know

A 10 foot ladder is leaning against a wall. Call x the distance from the top of the ladder to the ground, and call y the distanc

liq [111]

$-5.3\:\text{ft/s}$

Step-by-step explanation:

We start by applying the Pythagorean theorem to the ladder, with its length L as the hypotenuse:

$L^2 = 100\:\text{ft}^2 = x^2 + y^2$

where x is the vertical distance from the top of the ladder to the ground and y is the horizontal distance from the bottom of the ladder to the wall. Taking the derivative of the above expression with respect to time, we get

$0 = 2x\dfrac{dx}{dt} + 2y\dfrac{dy}{dt}$

Solving for dx/dt, we get

$\dfrac{dx}{dt} = -\left(\dfrac{y}{x}\right)\dfrac{dy}{dt} = -\left(\dfrac{\sqrt{L^2 - x^2}}{x}\right)\dfrac{dy}{dt}$

We know that

$\dfrac{dy}{dt} = 4\:\text{ft/s}$

when x = 6 ft. So the rate at which the top of the ladder is going down is

$\dfrac{dx}{dt} = -\left(\dfrac{\sqrt{100\:\text{ft}^2 - (6\:\text{ft})^2}}{6\:\text{ft}}\right)(4\:\text{ft/s})$

$\:\:\:\:\:\:\:= -5.3\:\text{ft/s}$

The negative sign means that the distance x is decreasing as y is increasing.

5 0

3 years ago

If the starting time is at 6:57 and the elapsed time is 47 minutes what is the end time??

Alex

The end time is 7:44. Hope this helps!

5 0

3 years ago

Solving systems by Substitution Homework y=x+4 y=x-3

zvonat [6]

There is no solution for this equation since they have the same slope, x/1. The only difference between these two is that their y intercepts are different meaning that they will be parallel lines that will never intersect among one other. For example, think of it as two separate lines that are have the same slope and never gain more distance/units from one another.

Solve:

To solve, you have to get one of this equations into a Ax+By=C equation form, standard equation. Let’s change y=x+4 into a standard equation.

We have to get x and y together and 4 as C.
So let’s subtract x from both sides;

y=x+4
-x -x
————————
-x+y=4

This is a standard equation.

Now let’s substitute.

take the standard equation and plug in y which is x+4 since there is a equation meaning it’s y=x+4

-x+(x+4)=4

Let’s simplify this mess.

-x+x equals 0. So we are left with 4=4.

Subtract 4 from both sides and we get 0=0

This means there is no solution. Hoped this helped.

8 0

3 years ago

What is the Product of this Sum: x+2x+3x

Tomtit [17]

The answer is 6x

Because x is equal to 1x so 1x+2x+3x = 6x

Hope this helps :)

8 0

2 years ago

Read 2 more answers

Match each polynomial expression to its additive inverse.

fomenos

Answer:

Step-by-step explanation:

To find the additive inverse of polynomial expression, flip the sign of each term.

6x² ----> -6x²

-x -----> +x

-2 -----> +2

Additive inverse:

-6x² + x + 2

6 0

4 years ago