Calculus Examples

Find the Horizontal Tangent Line y=x^3-4x^2+x+2
Step 1
Set as a function of .
Step 2
Find the derivative.
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Step 2.1
Differentiate.
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Step 2.1.1
By the Sum Rule, the derivative of with respect to is .
Step 2.1.2
Differentiate using the Power Rule which states that is where .
Step 2.2
Evaluate .
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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
Differentiate.
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Step 2.3.1
Differentiate using the Power Rule which states that is where .
Step 2.3.2
Since is constant with respect to , the derivative of with respect to is .
Step 2.3.3
Add and .
Step 3
Set the derivative equal to then solve the equation .
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Step 3.1
Use the quadratic formula to find the solutions.
Step 3.2
Substitute the values , , and into the quadratic formula and solve for .
Step 3.3
Simplify.
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Step 3.3.1
Simplify the numerator.
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Step 3.3.1.1
Raise to the power of .
Step 3.3.1.2
Multiply .
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Step 3.3.1.2.1
Multiply by .
Step 3.3.1.2.2
Multiply by .
Step 3.3.1.3
Subtract from .
Step 3.3.1.4
Rewrite as .
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Step 3.3.1.4.1
Factor out of .
Step 3.3.1.4.2
Rewrite as .
Step 3.3.1.5
Pull terms out from under the radical.
Step 3.3.2
Multiply by .
Step 3.3.3
Simplify .
Step 3.4
Simplify the expression to solve for the portion of the .
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Step 3.4.1
Simplify the numerator.
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Step 3.4.1.1
Raise to the power of .
Step 3.4.1.2
Multiply .
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Step 3.4.1.2.1
Multiply by .
Step 3.4.1.2.2
Multiply by .
Step 3.4.1.3
Subtract from .
Step 3.4.1.4
Rewrite as .
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Step 3.4.1.4.1
Factor out of .
Step 3.4.1.4.2
Rewrite as .
Step 3.4.1.5
Pull terms out from under the radical.
Step 3.4.2
Multiply by .
Step 3.4.3
Simplify .
Step 3.4.4
Change the to .
Step 3.5
Simplify the expression to solve for the portion of the .
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Step 3.5.1
Simplify the numerator.
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Step 3.5.1.1
Raise to the power of .
Step 3.5.1.2
Multiply .
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Step 3.5.1.2.1
Multiply by .
Step 3.5.1.2.2
Multiply by .
Step 3.5.1.3
Subtract from .
Step 3.5.1.4
Rewrite as .
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Step 3.5.1.4.1
Factor out of .
Step 3.5.1.4.2
Rewrite as .
Step 3.5.1.5
Pull terms out from under the radical.
Step 3.5.2
Multiply by .
Step 3.5.3
Simplify .
Step 3.5.4
Change the to .
Step 3.6
The final answer is the combination of both solutions.
Step 4
Solve the original function at .
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Step 4.1
Replace the variable with in the expression.
Step 4.2
Simplify the result.
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Step 4.2.1
Remove parentheses.
Step 4.2.2
Find the common denominator.
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Step 4.2.2.1
Write as a fraction with denominator .
Step 4.2.2.2
Multiply by .
Step 4.2.2.3
Multiply by .
Step 4.2.2.4
Write as a fraction with denominator .
Step 4.2.2.5
Multiply by .
Step 4.2.2.6
Multiply by .
Step 4.2.2.7
Write as a fraction with denominator .
Step 4.2.2.8
Multiply by .
Step 4.2.2.9
Multiply by .
Step 4.2.3
Combine the numerators over the common denominator.
Step 4.2.4
Simplify each term.
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Step 4.2.4.1
Apply the product rule to .
Step 4.2.4.2
Raise to the power of .
Step 4.2.4.3
Cancel the common factor of .
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Step 4.2.4.3.1
Factor out of .
Step 4.2.4.3.2
Cancel the common factor.
Step 4.2.4.3.3
Rewrite the expression.
Step 4.2.4.4
Use the Binomial Theorem.
Step 4.2.4.5
Simplify each term.
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Step 4.2.4.5.1
Raise to the power of .
Step 4.2.4.5.2
Raise to the power of .
Step 4.2.4.5.3
Multiply by .
Step 4.2.4.5.4
Multiply by .
Step 4.2.4.5.5
Rewrite as .
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Step 4.2.4.5.5.1
Use to rewrite as .
Step 4.2.4.5.5.2
Apply the power rule and multiply exponents, .
Step 4.2.4.5.5.3
Combine and .
Step 4.2.4.5.5.4
Cancel the common factor of .
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Step 4.2.4.5.5.4.1
Cancel the common factor.
Step 4.2.4.5.5.4.2
Rewrite the expression.
Step 4.2.4.5.5.5
Evaluate the exponent.
Step 4.2.4.5.6
Multiply by .
Step 4.2.4.5.7
Rewrite as .
Step 4.2.4.5.8
Raise to the power of .
Step 4.2.4.5.9
Rewrite as .
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Step 4.2.4.5.9.1
Factor out of .
Step 4.2.4.5.9.2
Rewrite as .
Step 4.2.4.5.10
Pull terms out from under the radical.
Step 4.2.4.6
Add and .
Step 4.2.4.7
Add and .
Step 4.2.4.8
Apply the product rule to .
Step 4.2.4.9
Raise to the power of .
Step 4.2.4.10
Rewrite as .
Step 4.2.4.11
Expand using the FOIL Method.
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Step 4.2.4.11.1
Apply the distributive property.
Step 4.2.4.11.2
Apply the distributive property.
Step 4.2.4.11.3
Apply the distributive property.
Step 4.2.4.12
Simplify and combine like terms.
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Step 4.2.4.12.1
Simplify each term.
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Step 4.2.4.12.1.1
Multiply by .
Step 4.2.4.12.1.2
Move to the left of .
Step 4.2.4.12.1.3
Combine using the product rule for radicals.
Step 4.2.4.12.1.4
Multiply by .
Step 4.2.4.12.1.5
Rewrite as .
Step 4.2.4.12.1.6
Pull terms out from under the radical, assuming positive real numbers.
Step 4.2.4.12.2
Add and .
Step 4.2.4.12.3
Add and .
Step 4.2.4.13
Combine and .
Step 4.2.4.14
Cancel the common factor of .
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Step 4.2.4.14.1
Factor out of .
Step 4.2.4.14.2
Cancel the common factor.
Step 4.2.4.14.3
Rewrite the expression.
Step 4.2.4.15
Move the negative in front of the fraction.
Step 4.2.4.16
Multiply by .
Step 4.2.5
To write as a fraction with a common denominator, multiply by .
Step 4.2.6
Write each expression with a common denominator of , by multiplying each by an appropriate factor of .
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Step 4.2.6.1
Multiply by .
Step 4.2.6.2
Multiply by .
Step 4.2.7
Combine the numerators over the common denominator.
Step 4.2.8
Simplify the numerator.
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Step 4.2.8.1
Apply the distributive property.
Step 4.2.8.2
Multiply by .
Step 4.2.8.3
Multiply by .
Step 4.2.8.4
Apply the distributive property.
Step 4.2.8.5
Multiply by .
Step 4.2.8.6
Multiply by .
Step 4.2.8.7
Subtract from .
Step 4.2.8.8
Subtract from .
Step 4.2.9
To write as a fraction with a common denominator, multiply by .
Step 4.2.10
Combine and .
Step 4.2.11
Simplify the expression.
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Step 4.2.11.1
Combine the numerators over the common denominator.
Step 4.2.11.2
Multiply by .
Step 4.2.11.3
Add and .
Step 4.2.12
To write as a fraction with a common denominator, multiply by .
Step 4.2.13
Combine and .
Step 4.2.14
Simplify the expression.
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Step 4.2.14.1
Combine the numerators over the common denominator.
Step 4.2.14.2
Reorder the factors of .
Step 4.2.15
Add and .
Step 4.2.16
To write as a fraction with a common denominator, multiply by .
Step 4.2.17
Combine fractions.
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Step 4.2.17.1
Combine and .
Step 4.2.17.2
Combine the numerators over the common denominator.
Step 4.2.18
Simplify the numerator.
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Step 4.2.18.1
Multiply by .
Step 4.2.18.2
Add and .
Step 4.2.19
Simplify with factoring out.
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Step 4.2.19.1
Rewrite as .
Step 4.2.19.2
Factor out of .
Step 4.2.19.3
Factor out of .
Step 4.2.19.4
Move the negative in front of the fraction.
Step 4.2.20
Multiply the numerator by the reciprocal of the denominator.
Step 4.2.21
Multiply .
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Step 4.2.21.1
Multiply by .
Step 4.2.21.2
Multiply by .
Step 4.2.22
The final answer is .
Step 5
Solve the original function at .
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Step 5.1
Replace the variable with in the expression.
Step 5.2
Simplify the result.
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Step 5.2.1
Remove parentheses.
Step 5.2.2
Find the common denominator.
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Step 5.2.2.1
Write as a fraction with denominator .
Step 5.2.2.2
Multiply by .
Step 5.2.2.3
Multiply by .
Step 5.2.2.4
Write as a fraction with denominator .
Step 5.2.2.5
Multiply by .
Step 5.2.2.6
Multiply by .
Step 5.2.2.7
Write as a fraction with denominator .
Step 5.2.2.8
Multiply by .
Step 5.2.2.9
Multiply by .
Step 5.2.3
Combine the numerators over the common denominator.
Step 5.2.4
Simplify each term.
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Step 5.2.4.1
Apply the product rule to .
Step 5.2.4.2
Raise to the power of .
Step 5.2.4.3
Cancel the common factor of .
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Step 5.2.4.3.1
Factor out of .
Step 5.2.4.3.2
Cancel the common factor.
Step 5.2.4.3.3
Rewrite the expression.
Step 5.2.4.4
Use the Binomial Theorem.
Step 5.2.4.5
Simplify each term.
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Step 5.2.4.5.1
Raise to the power of .
Step 5.2.4.5.2
Raise to the power of .
Step 5.2.4.5.3
Multiply by .
Step 5.2.4.5.4
Multiply by .
Step 5.2.4.5.5
Multiply by .
Step 5.2.4.5.6
Apply the product rule to .
Step 5.2.4.5.7
Raise to the power of .
Step 5.2.4.5.8
Multiply by .
Step 5.2.4.5.9
Rewrite as .
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Step 5.2.4.5.9.1
Use to rewrite as .
Step 5.2.4.5.9.2
Apply the power rule and multiply exponents, .
Step 5.2.4.5.9.3
Combine and .
Step 5.2.4.5.9.4
Cancel the common factor of .
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Step 5.2.4.5.9.4.1
Cancel the common factor.
Step 5.2.4.5.9.4.2
Rewrite the expression.
Step 5.2.4.5.9.5
Evaluate the exponent.
Step 5.2.4.5.10
Multiply by .
Step 5.2.4.5.11
Apply the product rule to .
Step 5.2.4.5.12
Raise to the power of .
Step 5.2.4.5.13
Rewrite as .
Step 5.2.4.5.14
Raise to the power of .
Step 5.2.4.5.15
Rewrite as .
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Step 5.2.4.5.15.1
Factor out of .
Step 5.2.4.5.15.2
Rewrite as .
Step 5.2.4.5.16
Pull terms out from under the radical.
Step 5.2.4.5.17
Multiply by .
Step 5.2.4.6
Add and .
Step 5.2.4.7
Subtract from .
Step 5.2.4.8
Apply the product rule to .
Step 5.2.4.9
Raise to the power of .
Step 5.2.4.10
Rewrite as .
Step 5.2.4.11
Expand using the FOIL Method.
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Step 5.2.4.11.1
Apply the distributive property.
Step 5.2.4.11.2
Apply the distributive property.
Step 5.2.4.11.3
Apply the distributive property.
Step 5.2.4.12
Simplify and combine like terms.
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Step 5.2.4.12.1
Simplify each term.
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Step 5.2.4.12.1.1
Multiply by .
Step 5.2.4.12.1.2
Multiply by .
Step 5.2.4.12.1.3
Multiply by .
Step 5.2.4.12.1.4
Multiply .
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Step 5.2.4.12.1.4.1
Multiply by .
Step 5.2.4.12.1.4.2
Multiply by .
Step 5.2.4.12.1.4.3
Raise to the power of .
Step 5.2.4.12.1.4.4
Raise to the power of .
Step 5.2.4.12.1.4.5
Use the power rule to combine exponents.
Step 5.2.4.12.1.4.6
Add and .
Step 5.2.4.12.1.5
Rewrite as .
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Step 5.2.4.12.1.5.1
Use to rewrite as .
Step 5.2.4.12.1.5.2
Apply the power rule and multiply exponents, .
Step 5.2.4.12.1.5.3
Combine and .
Step 5.2.4.12.1.5.4
Cancel the common factor of .
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Step 5.2.4.12.1.5.4.1
Cancel the common factor.
Step 5.2.4.12.1.5.4.2
Rewrite the expression.
Step 5.2.4.12.1.5.5
Evaluate the exponent.
Step 5.2.4.12.2
Add and .
Step 5.2.4.12.3
Subtract from .
Step 5.2.4.13
Combine and .
Step 5.2.4.14
Cancel the common factor of .
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Step 5.2.4.14.1
Factor out of .
Step 5.2.4.14.2
Cancel the common factor.
Step 5.2.4.14.3
Rewrite the expression.
Step 5.2.4.15
Move the negative in front of the fraction.
Step 5.2.4.16
Multiply by .
Step 5.2.5
To write as a fraction with a common denominator, multiply by .
Step 5.2.6
Write each expression with a common denominator of , by multiplying each by an appropriate factor of .
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Step 5.2.6.1
Multiply by .
Step 5.2.6.2
Multiply by .
Step 5.2.7
Combine the numerators over the common denominator.
Step 5.2.8
Simplify the numerator.
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Step 5.2.8.1
Apply the distributive property.
Step 5.2.8.2
Multiply by .
Step 5.2.8.3
Multiply by .
Step 5.2.8.4
Apply the distributive property.
Step 5.2.8.5
Multiply by .
Step 5.2.8.6
Multiply by .
Step 5.2.8.7
Subtract from .
Step 5.2.8.8
Add and .
Step 5.2.9
To write as a fraction with a common denominator, multiply by .
Step 5.2.10
Combine and .
Step 5.2.11
Simplify the expression.
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Step 5.2.11.1
Combine the numerators over the common denominator.
Step 5.2.11.2
Multiply by .
Step 5.2.11.3
Add and .
Step 5.2.12
To write as a fraction with a common denominator, multiply by .
Step 5.2.13
Combine fractions.
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Step 5.2.13.1
Combine and .
Step 5.2.13.2
Combine the numerators over the common denominator.
Step 5.2.14
Simplify the numerator.
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Step 5.2.14.1
Multiply by .
Step 5.2.14.2
Subtract from .
Step 5.2.15
To write as a fraction with a common denominator, multiply by .
Step 5.2.16
Combine fractions.
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Step 5.2.16.1
Combine and .
Step 5.2.16.2
Combine the numerators over the common denominator.
Step 5.2.17
Simplify the numerator.
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Step 5.2.17.1
Multiply by .
Step 5.2.17.2
Add and .
Step 5.2.18
Simplify with factoring out.
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Step 5.2.18.1
Rewrite as .
Step 5.2.18.2
Factor out of .
Step 5.2.18.3
Factor out of .
Step 5.2.18.4
Move the negative in front of the fraction.
Step 5.2.19
Multiply the numerator by the reciprocal of the denominator.
Step 5.2.20
Multiply .
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Step 5.2.20.1
Multiply by .
Step 5.2.20.2
Multiply by .
Step 5.2.21
The final answer is .
Step 6
The horizontal tangent lines on function are .
Step 7