Calculus Examples

Solve the Differential Equation (x^2+1)(dy)/(dx)+3x(y-1)=0 , y(0)=9
,
Step 1
Separate the variables.
Tap for more steps...
Step 1.1
Solve for .
Tap for more steps...
Step 1.1.1
Simplify each term.
Tap for more steps...
Step 1.1.1.1
Apply the distributive property.
Step 1.1.1.2
Multiply by .
Step 1.1.1.3
Apply the distributive property.
Step 1.1.1.4
Multiply by .
Step 1.1.2
Move all terms not containing to the right side of the equation.
Tap for more steps...
Step 1.1.2.1
Subtract from both sides of the equation.
Step 1.1.2.2
Add to both sides of the equation.
Step 1.1.3
Factor out of .
Tap for more steps...
Step 1.1.3.1
Factor out of .
Step 1.1.3.2
Raise to the power of .
Step 1.1.3.3
Factor out of .
Step 1.1.3.4
Factor out of .
Step 1.1.4
Divide each term in by and simplify.
Tap for more steps...
Step 1.1.4.1
Divide each term in by .
Step 1.1.4.2
Simplify the left side.
Tap for more steps...
Step 1.1.4.2.1
Cancel the common factor of .
Tap for more steps...
Step 1.1.4.2.1.1
Cancel the common factor.
Step 1.1.4.2.1.2
Divide by .
Step 1.1.4.3
Simplify the right side.
Tap for more steps...
Step 1.1.4.3.1
Combine the numerators over the common denominator.
Step 1.1.4.3.2
Simplify the numerator.
Tap for more steps...
Step 1.1.4.3.2.1
Factor out of .
Tap for more steps...
Step 1.1.4.3.2.1.1
Factor out of .
Step 1.1.4.3.2.1.2
Factor out of .
Step 1.1.4.3.2.1.3
Factor out of .
Step 1.1.4.3.2.2
Rewrite as .
Step 1.1.4.3.3
Simplify with factoring out.
Tap for more steps...
Step 1.1.4.3.3.1
Factor out of .
Step 1.1.4.3.3.2
Rewrite as .
Step 1.1.4.3.3.3
Factor out of .
Step 1.1.4.3.3.4
Simplify the expression.
Tap for more steps...
Step 1.1.4.3.3.4.1
Rewrite as .
Step 1.1.4.3.3.4.2
Move the negative in front of the fraction.
Step 1.2
Regroup factors.
Step 1.3
Multiply both sides by .
Step 1.4
Simplify.
Tap for more steps...
Step 1.4.1
Rewrite using the commutative property of multiplication.
Step 1.4.2
Cancel the common factor of .
Tap for more steps...
Step 1.4.2.1
Move the leading negative in into the numerator.
Step 1.4.2.2
Factor out of .
Step 1.4.2.3
Cancel the common factor.
Step 1.4.2.4
Rewrite the expression.
Step 1.5
Rewrite the equation.
Step 2
Integrate both sides.
Tap for more steps...
Step 2.1
Set up an integral on each side.
Step 2.2
Integrate the left side.
Tap for more steps...
Step 2.2.1
Let . Then . Rewrite using and .
Tap for more steps...
Step 2.2.1.1
Let . Find .
Tap for more steps...
Step 2.2.1.1.1
Differentiate .
Step 2.2.1.1.2
By the Sum Rule, the derivative of with respect to is .
Step 2.2.1.1.3
Differentiate using the Power Rule which states that is where .
Step 2.2.1.1.4
Since is constant with respect to , the derivative of with respect to is .
Step 2.2.1.1.5
Add and .
Step 2.2.1.2
Rewrite the problem using and .
Step 2.2.2
The integral of with respect to is .
Step 2.2.3
Replace all occurrences of with .
Step 2.3
Integrate the right side.
Tap for more steps...
Step 2.3.1
Since is constant with respect to , move out of the integral.
Step 2.3.2
Since is constant with respect to , move out of the integral.
Step 2.3.3
Multiply by .
Step 2.3.4
Let . Then , so . Rewrite using and .
Tap for more steps...
Step 2.3.4.1
Let . Find .
Tap for more steps...
Step 2.3.4.1.1
Differentiate .
Step 2.3.4.1.2
By the Sum Rule, the derivative of with respect to is .
Step 2.3.4.1.3
Differentiate using the Power Rule which states that is where .
Step 2.3.4.1.4
Since is constant with respect to , the derivative of with respect to is .
Step 2.3.4.1.5
Add and .
Step 2.3.4.2
Rewrite the problem using and .
Step 2.3.5
Simplify.
Tap for more steps...
Step 2.3.5.1
Multiply by .
Step 2.3.5.2
Move to the left of .
Step 2.3.6
Since is constant with respect to , move out of the integral.
Step 2.3.7
Simplify.
Tap for more steps...
Step 2.3.7.1
Combine and .
Step 2.3.7.2
Move the negative in front of the fraction.
Step 2.3.8
The integral of with respect to is .
Step 2.3.9
Simplify.
Step 2.3.10
Replace all occurrences of with .
Step 2.4
Group the constant of integration on the right side as .
Step 3
Solve for .
Tap for more steps...
Step 3.1
Simplify the right side.
Tap for more steps...
Step 3.1.1
Simplify each term.
Tap for more steps...
Step 3.1.1.1
Combine and .
Step 3.1.1.2
Move to the left of .
Step 3.2
Move all the terms containing a logarithm to the left side of the equation.
Step 3.3
To write as a fraction with a common denominator, multiply by .
Step 3.4
Simplify terms.
Tap for more steps...
Step 3.4.1
Combine and .
Step 3.4.2
Combine the numerators over the common denominator.
Step 3.5
Move to the left of .
Step 3.6
Simplify the left side.
Tap for more steps...
Step 3.6.1
Simplify .
Tap for more steps...
Step 3.6.1.1
Simplify the numerator.
Tap for more steps...
Step 3.6.1.1.1
Simplify by moving inside the logarithm.
Step 3.6.1.1.2
Remove the absolute value in because exponentiations with even powers are always positive.
Step 3.6.1.1.3
Simplify by moving inside the logarithm.
Step 3.6.1.1.4
Use the product property of logarithms, .
Step 3.6.1.2
Rewrite as .
Step 3.6.1.3
Simplify by moving inside the logarithm.
Step 3.6.1.4
Apply the product rule to .
Step 3.6.1.5
Multiply the exponents in .
Tap for more steps...
Step 3.6.1.5.1
Apply the power rule and multiply exponents, .
Step 3.6.1.5.2
Cancel the common factor of .
Tap for more steps...
Step 3.6.1.5.2.1
Cancel the common factor.
Step 3.6.1.5.2.2
Rewrite the expression.
Step 3.6.1.6
Simplify.
Step 3.6.1.7
Multiply the exponents in .
Tap for more steps...
Step 3.6.1.7.1
Apply the power rule and multiply exponents, .
Step 3.6.1.7.2
Combine and .
Step 3.6.1.8
Apply the distributive property.
Step 3.6.1.9
Rewrite as .
Step 3.7
To solve for , rewrite the equation using properties of logarithms.
Step 3.8
Rewrite in exponential form using the definition of a logarithm. If and are positive real numbers and , then is equivalent to .
Step 3.9
Solve for .
Tap for more steps...
Step 3.9.1
Rewrite the equation as .
Step 3.9.2
Add to both sides of the equation.
Step 3.9.3
Divide each term in by and simplify.
Tap for more steps...
Step 3.9.3.1
Divide each term in by .
Step 3.9.3.2
Simplify the left side.
Tap for more steps...
Step 3.9.3.2.1
Cancel the common factor.
Step 3.9.3.2.2
Divide by .
Step 3.9.3.3
Simplify the right side.
Tap for more steps...
Step 3.9.3.3.1
Combine the numerators over the common denominator.
Step 4
Simplify the constant of integration.
Step 5
Use the initial condition to find the value of by substituting for and for in .
Step 6
Solve for .
Tap for more steps...
Step 6.1
Rewrite the equation as .
Step 6.2
Multiply both sides of the equation by .
Step 6.3
Simplify both sides of the equation.
Tap for more steps...
Step 6.3.1
Simplify the left side.
Tap for more steps...
Step 6.3.1.1
Simplify .
Tap for more steps...
Step 6.3.1.1.1
Cancel the common factor of .
Tap for more steps...
Step 6.3.1.1.1.1
Cancel the common factor.
Step 6.3.1.1.1.2
Rewrite the expression.
Step 6.3.1.1.2
Simplify each term.
Tap for more steps...
Step 6.3.1.1.2.1
Raising to any positive power yields .
Step 6.3.1.1.2.2
Add and .
Step 6.3.1.1.2.3
The absolute value is the distance between a number and zero. The distance between and is .
Step 6.3.1.1.2.4
One to any power is one.
Step 6.3.2
Simplify the right side.
Tap for more steps...
Step 6.3.2.1
Simplify .
Tap for more steps...
Step 6.3.2.1.1
Raising to any positive power yields .
Step 6.3.2.1.2
Add and .
Step 6.3.2.1.3
The absolute value is the distance between a number and zero. The distance between and is .
Step 6.3.2.1.4
One to any power is one.
Step 6.3.2.1.5
Multiply by .
Step 6.4
Move all terms not containing to the right side of the equation.
Tap for more steps...
Step 6.4.1
Subtract from both sides of the equation.
Step 6.4.2
Subtract from .
Step 7
Substitute for in and simplify.
Tap for more steps...
Step 7.1
Substitute for .
Step 7.2
Simplify the numerator.
Tap for more steps...
Step 7.2.1
Rewrite as .
Step 7.2.2
Rewrite as .
Step 7.2.3
Since both terms are perfect cubes, factor using the sum of cubes formula, where and .
Step 7.2.4
Simplify.
Tap for more steps...
Step 7.2.4.1
Raise to the power of .
Step 7.2.4.2
Multiply the exponents in .
Tap for more steps...
Step 7.2.4.2.1
Apply the power rule and multiply exponents, .
Step 7.2.4.2.2
Cancel the common factor of .
Tap for more steps...
Step 7.2.4.2.2.1
Cancel the common factor.
Step 7.2.4.2.2.2
Rewrite the expression.
Step 7.2.4.3
Simplify.
Step 7.2.4.4
Reorder terms.