Calculus Examples

Find the Local Maxima and Minima 4x^3+3x^2-6x+1
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
Evaluate .
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
Differentiate using the Power Rule which states that is where .
Step 2.4.3
Multiply by .
Step 2.5
Differentiate using the Constant Rule.
Tap for more steps...
Step 2.5.1
Since is constant with respect to , the derivative of with respect to is .
Step 2.5.2
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 3.4
Differentiate using the Constant Rule.
Tap for more steps...
Step 3.4.1
Since is constant with respect to , the derivative of with respect to is .
Step 3.4.2
Add and .
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
Evaluate .
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
Differentiate using the Power Rule which states that is where .
Step 5.1.4.3
Multiply by .
Step 5.1.5
Differentiate using the Constant Rule.
Tap for more steps...
Step 5.1.5.1
Since is constant with respect to , the derivative of with respect to is .
Step 5.1.5.2
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 the left side of the equation.
Tap for more steps...
Step 6.2.1
Factor out of .
Tap for more steps...
Step 6.2.1.1
Factor out of .
Step 6.2.1.2
Factor out of .
Step 6.2.1.3
Factor out of .
Step 6.2.1.4
Factor out of .
Step 6.2.1.5
Factor out of .
Step 6.2.2
Factor.
Tap for more steps...
Step 6.2.2.1
Factor by grouping.
Tap for more steps...
Step 6.2.2.1.1
For a polynomial of the form , rewrite the middle term as a sum of two terms whose product is and whose sum is .
Tap for more steps...
Step 6.2.2.1.1.1
Multiply by .
Step 6.2.2.1.1.2
Rewrite as plus
Step 6.2.2.1.1.3
Apply the distributive property.
Step 6.2.2.1.2
Factor out the greatest common factor from each group.
Tap for more steps...
Step 6.2.2.1.2.1
Group the first two terms and the last two terms.
Step 6.2.2.1.2.2
Factor out the greatest common factor (GCF) from each group.
Step 6.2.2.1.3
Factor the polynomial by factoring out the greatest common factor, .
Step 6.2.2.2
Remove unnecessary parentheses.
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 and solve for .
Tap for more steps...
Step 6.4.1
Set equal to .
Step 6.4.2
Solve for .
Tap for more steps...
Step 6.4.2.1
Add to both sides of the equation.
Step 6.4.2.2
Divide each term in by and simplify.
Tap for more steps...
Step 6.4.2.2.1
Divide each term in by .
Step 6.4.2.2.2
Simplify the left side.
Tap for more steps...
Step 6.4.2.2.2.1
Cancel the common factor of .
Tap for more steps...
Step 6.4.2.2.2.1.1
Cancel the common factor.
Step 6.4.2.2.2.1.2
Divide by .
Step 6.5
Set equal to and solve for .
Tap for more steps...
Step 6.5.1
Set equal to .
Step 6.5.2
Subtract from both sides of the equation.
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
Cancel the common factor of .
Tap for more steps...
Step 10.1.1
Factor out of .
Step 10.1.2
Cancel the common factor.
Step 10.1.3
Rewrite the expression.
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
Apply the product rule to .
Step 12.2.1.2
One to any power is one.
Step 12.2.1.3
Raise to the power of .
Step 12.2.1.4
Cancel the common factor of .
Tap for more steps...
Step 12.2.1.4.1
Factor out of .
Step 12.2.1.4.2
Cancel the common factor.
Step 12.2.1.4.3
Rewrite the expression.
Step 12.2.1.5
Apply the product rule to .
Step 12.2.1.6
One to any power is one.
Step 12.2.1.7
Raise to the power of .
Step 12.2.1.8
Combine and .
Step 12.2.1.9
Cancel the common factor of .
Tap for more steps...
Step 12.2.1.9.1
Factor out of .
Step 12.2.1.9.2
Cancel the common factor.
Step 12.2.1.9.3
Rewrite the expression.
Step 12.2.2
Find the common denominator.
Tap for more steps...
Step 12.2.2.1
Multiply by .
Step 12.2.2.2
Multiply by .
Step 12.2.2.3
Write as a fraction with denominator .
Step 12.2.2.4
Multiply by .
Step 12.2.2.5
Multiply by .
Step 12.2.2.6
Write as a fraction with denominator .
Step 12.2.2.7
Multiply by .
Step 12.2.2.8
Multiply by .
Step 12.2.2.9
Multiply by .
Step 12.2.3
Combine the numerators over the common denominator.
Step 12.2.4
Simplify the expression.
Tap for more steps...
Step 12.2.4.1
Multiply by .
Step 12.2.4.2
Add and .
Step 12.2.4.3
Subtract from .
Step 12.2.4.4
Add and .
Step 12.2.4.5
Move the negative in front of the fraction.
Step 12.2.5
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
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
Raise to the power of .
Step 16.2.1.2
Multiply by .
Step 16.2.1.3
Raise to the power of .
Step 16.2.1.4
Multiply by .
Step 16.2.1.5
Multiply by .
Step 16.2.2
Simplify by adding numbers.
Tap for more steps...
Step 16.2.2.1
Add and .
Step 16.2.2.2
Add and .
Step 16.2.2.3
Add and .
Step 16.2.3
The final answer is .
Step 17
These are the local extrema for .
is a local minima
is a local maxima
Step 18