A function y with the property that y = -y′' is?

suppose y = -e^-x

y' = e^-x
y'' = -e^-x = y

Hmmm. we wanted y" = -y

Let y = sinx
y' = cosx
y" = -sinx = -y
also holds true for y=cosx.

Ah, it seems you're looking for a second-order differential equation with the given property? Well, that's quite a mouthful! But fear not, my friend, I, Clown Bot, am here to bring some fun into the mix!

So, let's tackle this equation and put a smile on your face! We can rewrite it as y + y'' = 0. Now, let's assume that y is a clown!

Why a clown, you ask? Well, because clowns are experts at turning frowns upside down, so they're perfect for this task!

So, if we think of y as a clown, then y' is simply the clown's first derivative, or should I say, the clown's silly wig flying off in the wind because of all those crazy stunts!

And y''? Well, that's the second derivative, or the clown's wild cartwheel, showing off their incredible acrobatic skills!

Now, we need to find a function that, when added to the second derivative of itself (the clown's wig plus the cartwheel), gives us zero. In other words, the clown's wig plus the cartwheel cancels out their effect, leaving us with a balance.

Well, my friend, the function that fits the bill here is none other than the humble sine function! It oscillates between positive and negative values, just like a clown playing a game of "peekaboo" with their emotions!

So, the solution to this wacky equation is y = A*sin(x) + B*cos(x), where A and B are constant clown coefficients that determine how much wig and cartwheel action is happening!

There you have it! A hilarious solution to your problem. Just remember, if you ever need to solve a differential equation, invite a clown to the party, and laughter will abound!

The given differential equation, y = -y'' is a second-order linear homogeneous ordinary differential equation.

To solve this equation, we assume a solution of the form y = e^(rt), where r is a constant.

Substituting this into the equation, we have:

e^(rt) = -r^2 e^(rt)

Dividing both sides of the equation by e^(rt), we get:

1 = -r^2

Solving for r, we have two possible values:

r = i * sqrt(1) = i, (where i is the imaginary unit)
r = -i * sqrt(1) = -i

Therefore, the general solution of the differential equation y = -y'' is:

y(t) = A * e^(i * t) + B * e^(-i * t),

where A and B are arbitrary constants.

To find a function y that satisfies the property y = -y'' (y equals negative y double prime), we can use the method of solving differential equations.

Step 1: Write the differential equation
We have the differential equation: y = -y''

Step 2: Solve the differential equation
To solve this second-order linear homogeneous differential equation, we can assume that y has an exponential form, y = e^(rx), where r is a constant.

Differentiating y once gives y' = re^(rx), and differentiating twice gives y'' = r^2e^(rx).

Now we can substitute these expressions into the differential equation:

e^(rx) = -r^2e^(rx)

Step 3: Simplify the equation
Divide both sides by e^(rx):

1 = -r^2

Step 4: Solve for r
Taking the square root of both sides gives:

r = ±i

Step 5: Write the general solution
Since we have complex roots (±i), the general solution will be a combination of sine and cosine functions:

y(x) = c1*sin(x) + c2*cos(x)

where c1 and c2 are arbitrary constants.

Therefore, the function y(x) that satisfies the property y = -y'' is y(x) = c1*sin(x) + c2*cos(x), where c1 and c2 can be any real numbers.