Calculus Examples

Find the Local Maxima and Minima y=-x^4+4x^2-10
Step 1
Write as a function.
Step 2
Find the first derivative of the function.
Tap for more steps...
Step 2.1
By the Sum Rule, the derivative of with respect to is .
Step 2.2
Evaluate .
Tap for more steps...
Step 2.2.1
Since is constant with respect to , the derivative of with respect to is .
Step 2.2.2
Differentiate using the Power Rule which states that is where .
Step 2.2.3
Multiply by .
Step 2.3
Evaluate .
Tap for more steps...
Step 2.3.1
Since is constant with respect to , the derivative of with respect to is .
Step 2.3.2
Differentiate using the Power Rule which states that is where .
Step 2.3.3
Multiply by .
Step 2.4
Differentiate using the Constant Rule.
Tap for more steps...
Step 2.4.1
Since is constant with respect to , the derivative of with respect to is .
Step 2.4.2
Add and .
Step 3
Find the second derivative of the function.
Tap for more steps...
Step 3.1
By the Sum Rule, the derivative of with respect to is .
Step 3.2
Evaluate .
Tap for more steps...
Step 3.2.1
Since is constant with respect to , the derivative of with respect to is .
Step 3.2.2
Differentiate using the Power Rule which states that is where .
Step 3.2.3
Multiply by .
Step 3.3
Evaluate .
Tap for more steps...
Step 3.3.1
Since is constant with respect to , the derivative of with respect to is .
Step 3.3.2
Differentiate using the Power Rule which states that is where .
Step 3.3.3
Multiply by .
Step 4
To find the local maximum and minimum values of the function, set the derivative equal to and solve.
Step 5
Find the first derivative.
Tap for more steps...
Step 5.1
Find the first derivative.
Tap for more steps...
Step 5.1.1
By the Sum Rule, the derivative of with respect to is .
Step 5.1.2
Evaluate .
Tap for more steps...
Step 5.1.2.1
Since is constant with respect to , the derivative of with respect to is .
Step 5.1.2.2
Differentiate using the Power Rule which states that is where .
Step 5.1.2.3
Multiply by .
Step 5.1.3
Evaluate .
Tap for more steps...
Step 5.1.3.1
Since is constant with respect to , the derivative of with respect to is .
Step 5.1.3.2
Differentiate using the Power Rule which states that is where .
Step 5.1.3.3
Multiply by .
Step 5.1.4
Differentiate using the Constant Rule.
Tap for more steps...
Step 5.1.4.1
Since is constant with respect to , the derivative of with respect to is .
Step 5.1.4.2
Add and .
Step 5.2
The first derivative of with respect to is .
Step 6
Set the first derivative equal to then solve the equation .
Tap for more steps...
Step 6.1
Set the first derivative equal to .
Step 6.2
Factor out of .
Tap for more steps...
Step 6.2.1
Factor out of .
Step 6.2.2
Factor out of .
Step 6.2.3
Factor out of .
Step 6.3
If any individual factor on the left side of the equation is equal to , the entire expression will be equal to .
Step 6.4
Set equal to .
Step 6.5
Set equal to and solve for .
Tap for more steps...
Step 6.5.1
Set equal to .
Step 6.5.2
Solve for .
Tap for more steps...
Step 6.5.2.1
Add to both sides of the equation.
Step 6.5.2.2
Take the specified root of both sides of the equation to eliminate the exponent on the left side.
Step 6.5.2.3
The complete solution is the result of both the positive and negative portions of the solution.
Tap for more steps...
Step 6.5.2.3.1
First, use the positive value of the to find the first solution.
Step 6.5.2.3.2
Next, use the negative value of the to find the second solution.
Step 6.5.2.3.3
The complete solution is the result of both the positive and negative portions of the solution.
Step 6.6
The final solution is all the values that make true.
Step 7
Find the values where the derivative is undefined.
Tap for more steps...
Step 7.1
The domain of the expression is all real numbers except where the expression is undefined. In this case, there is no real number that makes the expression undefined.
Step 8
Critical points to evaluate.
Step 9
Evaluate the second derivative at . If the second derivative is positive, then this is a local minimum. If it is negative, then this is a local maximum.
Step 10
Evaluate the second derivative.
Tap for more steps...
Step 10.1
Simplify each term.
Tap for more steps...
Step 10.1.1
Raising to any positive power yields .
Step 10.1.2
Multiply by .
Step 10.2
Add and .
Step 11
is a local minimum because the value of the second derivative is positive. This is referred to as the second derivative test.
is a local minimum
Step 12
Find the y-value when .
Tap for more steps...
Step 12.1
Replace the variable with in the expression.
Step 12.2
Simplify the result.
Tap for more steps...
Step 12.2.1
Simplify each term.
Tap for more steps...
Step 12.2.1.1
Raising to any positive power yields .
Step 12.2.1.2
Multiply by .
Step 12.2.1.3
Raising to any positive power yields .
Step 12.2.1.4
Multiply by .
Step 12.2.2
Simplify by adding and subtracting.
Tap for more steps...
Step 12.2.2.1
Add and .
Step 12.2.2.2
Subtract from .
Step 12.2.3
The final answer is .
Step 13
Evaluate the second derivative at . If the second derivative is positive, then this is a local minimum. If it is negative, then this is a local maximum.
Step 14
Evaluate the second derivative.
Tap for more steps...
Step 14.1
Simplify each term.
Tap for more steps...
Step 14.1.1
Rewrite as .
Tap for more steps...
Step 14.1.1.1
Use to rewrite as .
Step 14.1.1.2
Apply the power rule and multiply exponents, .
Step 14.1.1.3
Combine and .
Step 14.1.1.4
Cancel the common factor of .
Tap for more steps...
Step 14.1.1.4.1
Cancel the common factor.
Step 14.1.1.4.2
Rewrite the expression.
Step 14.1.1.5
Evaluate the exponent.
Step 14.1.2
Multiply by .
Step 14.2
Add and .
Step 15
is a local maximum because the value of the second derivative is negative. This is referred to as the second derivative test.
is a local maximum
Step 16
Find the y-value when .
Tap for more steps...
Step 16.1
Replace the variable with in the expression.
Step 16.2
Simplify the result.
Tap for more steps...
Step 16.2.1
Simplify each term.
Tap for more steps...
Step 16.2.1.1
Rewrite as .
Tap for more steps...
Step 16.2.1.1.1
Use to rewrite as .
Step 16.2.1.1.2
Apply the power rule and multiply exponents, .
Step 16.2.1.1.3
Combine and .
Step 16.2.1.1.4
Cancel the common factor of and .
Tap for more steps...
Step 16.2.1.1.4.1
Factor out of .
Step 16.2.1.1.4.2
Cancel the common factors.
Tap for more steps...
Step 16.2.1.1.4.2.1
Factor out of .
Step 16.2.1.1.4.2.2
Cancel the common factor.
Step 16.2.1.1.4.2.3
Rewrite the expression.
Step 16.2.1.1.4.2.4
Divide by .
Step 16.2.1.2
Raise to the power of .
Step 16.2.1.3
Multiply by .
Step 16.2.1.4
Rewrite as .
Tap for more steps...
Step 16.2.1.4.1
Use to rewrite as .
Step 16.2.1.4.2
Apply the power rule and multiply exponents, .
Step 16.2.1.4.3
Combine and .
Step 16.2.1.4.4
Cancel the common factor of .
Tap for more steps...
Step 16.2.1.4.4.1
Cancel the common factor.
Step 16.2.1.4.4.2
Rewrite the expression.
Step 16.2.1.4.5
Evaluate the exponent.
Step 16.2.1.5
Multiply by .
Step 16.2.2
Simplify by adding and subtracting.
Tap for more steps...
Step 16.2.2.1
Add and .
Step 16.2.2.2
Subtract from .
Step 16.2.3
The final answer is .
Step 17
Evaluate the second derivative at . If the second derivative is positive, then this is a local minimum. If it is negative, then this is a local maximum.
Step 18
Evaluate the second derivative.
Tap for more steps...
Step 18.1
Simplify each term.
Tap for more steps...
Step 18.1.1
Apply the product rule to .
Step 18.1.2
Raise to the power of .
Step 18.1.3
Multiply by .
Step 18.1.4
Rewrite as .
Tap for more steps...
Step 18.1.4.1
Use to rewrite as .
Step 18.1.4.2
Apply the power rule and multiply exponents, .
Step 18.1.4.3
Combine and .
Step 18.1.4.4
Cancel the common factor of .
Tap for more steps...
Step 18.1.4.4.1
Cancel the common factor.
Step 18.1.4.4.2
Rewrite the expression.
Step 18.1.4.5
Evaluate the exponent.
Step 18.1.5
Multiply by .
Step 18.2
Add and .
Step 19
is a local maximum because the value of the second derivative is negative. This is referred to as the second derivative test.
is a local maximum
Step 20
Find the y-value when .
Tap for more steps...
Step 20.1
Replace the variable with in the expression.
Step 20.2
Simplify the result.
Tap for more steps...
Step 20.2.1
Simplify each term.
Tap for more steps...
Step 20.2.1.1
Apply the product rule to .
Step 20.2.1.2
Multiply by by adding the exponents.
Tap for more steps...
Step 20.2.1.2.1
Move .
Step 20.2.1.2.2
Multiply by .
Tap for more steps...
Step 20.2.1.2.2.1
Raise to the power of .
Step 20.2.1.2.2.2
Use the power rule to combine exponents.
Step 20.2.1.2.3
Add and .
Step 20.2.1.3
Raise to the power of .
Step 20.2.1.4
Rewrite as .
Tap for more steps...
Step 20.2.1.4.1
Use to rewrite as .
Step 20.2.1.4.2
Apply the power rule and multiply exponents, .
Step 20.2.1.4.3
Combine and .
Step 20.2.1.4.4
Cancel the common factor of and .
Tap for more steps...
Step 20.2.1.4.4.1
Factor out of .
Step 20.2.1.4.4.2
Cancel the common factors.
Tap for more steps...
Step 20.2.1.4.4.2.1
Factor out of .
Step 20.2.1.4.4.2.2
Cancel the common factor.
Step 20.2.1.4.4.2.3
Rewrite the expression.
Step 20.2.1.4.4.2.4
Divide by .
Step 20.2.1.5
Raise to the power of .
Step 20.2.1.6
Multiply by .
Step 20.2.1.7
Apply the product rule to .
Step 20.2.1.8
Raise to the power of .
Step 20.2.1.9
Multiply by .
Step 20.2.1.10
Rewrite as .
Tap for more steps...
Step 20.2.1.10.1
Use to rewrite as .
Step 20.2.1.10.2
Apply the power rule and multiply exponents, .
Step 20.2.1.10.3
Combine and .
Step 20.2.1.10.4
Cancel the common factor of .
Tap for more steps...
Step 20.2.1.10.4.1
Cancel the common factor.
Step 20.2.1.10.4.2
Rewrite the expression.
Step 20.2.1.10.5
Evaluate the exponent.
Step 20.2.1.11
Multiply by .
Step 20.2.2
Simplify by adding and subtracting.
Tap for more steps...
Step 20.2.2.1
Add and .
Step 20.2.2.2
Subtract from .
Step 20.2.3
The final answer is .
Step 21
These are the local extrema for .
is a local minima
is a local maxima
is a local maxima
Step 22