Ifdy/dx = x - y2 and y(0) = 1, then y(0.1) correct upto two decimal pl...
Given:
$\frac{dy}{dx} = x - y^2$
$y(0) = 1$
To Find:
$y(0.1)$ correct up to two decimal places.
Explanation:
To solve this differential equation, we can use the method of separation of variables.
Separating the variables, we get:
$\frac{dy}{1-y^2} = x \, dx$
Integration:
Integrating both sides with respect to their respective variables, we get:
$\int{\frac{dy}{1-y^2}} = \int{x \, dx}$
LHS Integration:
To integrate the left-hand side, we can use partial fraction decomposition. The general form of the partial fraction decomposition is:
$\frac{A}{y-1} + \frac{B}{y+1}$
Multiplying through by the common denominator $(y-1)(y+1)$, we get:
$1 = A(y+1) + B(y-1)$
Expanding and equating the coefficients of like terms, we get:
$1 = (A + B)y + (A - B)$
Comparing the coefficients of 'y', we get:
$A + B = 0 \implies A = -B$
Comparing the constants, we get:
$A - B = 1$
Solving these equations, we find:
$A = \frac{1}{2}$ and $B = -\frac{1}{2}$
Substituting these values back into the partial fraction decomposition, we get:
$\frac{\frac{1}{2}}{y-1} - \frac{\frac{1}{2}}{y+1}$
Integrating each term separately, we get:
$\frac{1}{2}\ln|y-1| - \frac{1}{2}\ln|y+1|$
RHS Integration:
Integrating the right-hand side, we get:
$\int{x \, dx} = \frac{x^2}{2} + C_1$
Combining the Integrals:
Substituting the integrals back into the original equation, we get:
$\frac{1}{2}\ln|y-1| - \frac{1}{2}\ln|y+1| = \frac{x^2}{2} + C_1$
Simplifying the equation, we get:
$\ln\left|\frac{y-1}{y+1}\right| = x^2 + C_1$
Applying Initial Condition:
Now, we can apply the initial condition $y(0) = 1$.
Plugging in the values, we get:
$\ln\left|\frac{1-1}{1+1}\right| = 0^2 + C_1$
Simplifying, we get:
$\ln\left|\frac{0}{2}\right| = C_1$
Which further simplifies to:
$\ln(0) = C_1$
The natural logarithm of 0 is undefined. Therefore, $C_1$ is undefined.
Solving for y:
Now, we can solve the equation for y.
Taking the exponent of both sides, we get:
Ifdy/dx = x - y2 and y(0) = 1, then y(0.1) correct upto two decimal pl...
Concept:
Euler's Method to generate a numerical solution to an initial value problem of the form:
y' = f (x, y), y(x0) = y0
yn + 1 = yn + h f(xn, yn)
Calculation:
We have,
x0 = 0, y0 = 1, h = 0.1
x1 = x0 + h
For n = 0
⇒ y1 = y0 + hf(xn, yn)
⇒ y1 = 1 - 0.1 × (0 - 1)2
⇒ y1 = 1 - 0.1
⇒ y1 = 0. 9
For n = 1
⇒ y2 = y1 + hf(x1 - y12)
⇒ y2 = 0.9 + 0.1[0.1 - (0.9)2]
⇒ y2 = 0.9 + 0.1[0.1 - 0. 81]
⇒ y2 = 0.9 - 0.1 × 0.71
⇒ y2 = 0.9 - 0.071
⇒ y2 = 0. 829
⇒ y2 = 0.83
∴ The approximately. two decimal place value is 0.83