Calculus Examples

Find the Absolute Max and Min over the Interval y=x^4-3x^2+4 ;, [-1,1]
y=x4-3x2+4 ;, [-1,1]
Step 1
Find the critical points.
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Step 1.1
Find the first derivative.
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Step 1.1.1
Find the first derivative.
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Step 1.1.1.1
Differentiate.
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Step 1.1.1.1.1
By the Sum Rule, the derivative of x4-3x2+4 with respect to x is ddx[x4]+ddx[-3x2]+ddx[4].
ddx[x4]+ddx[-3x2]+ddx[4]
Step 1.1.1.1.2
Differentiate using the Power Rule which states that ddx[xn] is nxn-1 where n=4.
4x3+ddx[-3x2]+ddx[4]
4x3+ddx[-3x2]+ddx[4]
Step 1.1.1.2
Evaluate ddx[-3x2].
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Step 1.1.1.2.1
Since -3 is constant with respect to x, the derivative of -3x2 with respect to x is -3ddx[x2].
4x3-3ddx[x2]+ddx[4]
Step 1.1.1.2.2
Differentiate using the Power Rule which states that ddx[xn] is nxn-1 where n=2.
4x3-3(2x)+ddx[4]
Step 1.1.1.2.3
Multiply 2 by -3.
4x3-6x+ddx[4]
4x3-6x+ddx[4]
Step 1.1.1.3
Differentiate using the Constant Rule.
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Step 1.1.1.3.1
Since 4 is constant with respect to x, the derivative of 4 with respect to x is 0.
4x3-6x+0
Step 1.1.1.3.2
Add 4x3-6x and 0.
f(x)=4x3-6x
f(x)=4x3-6x
f(x)=4x3-6x
Step 1.1.2
The first derivative of f(x) with respect to x is 4x3-6x.
4x3-6x
4x3-6x
Step 1.2
Set the first derivative equal to 0 then solve the equation 4x3-6x=0.
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Step 1.2.1
Set the first derivative equal to 0.
4x3-6x=0
Step 1.2.2
Factor 2x out of 4x3-6x.
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Step 1.2.2.1
Factor 2x out of 4x3.
2x(2x2)-6x=0
Step 1.2.2.2
Factor 2x out of -6x.
2x(2x2)+2x(-3)=0
Step 1.2.2.3
Factor 2x out of 2x(2x2)+2x(-3).
2x(2x2-3)=0
2x(2x2-3)=0
Step 1.2.3
If any individual factor on the left side of the equation is equal to 0, the entire expression will be equal to 0.
x=0
2x2-3=0
Step 1.2.4
Set x equal to 0.
x=0
Step 1.2.5
Set 2x2-3 equal to 0 and solve for x.
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Step 1.2.5.1
Set 2x2-3 equal to 0.
2x2-3=0
Step 1.2.5.2
Solve 2x2-3=0 for x.
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Step 1.2.5.2.1
Add 3 to both sides of the equation.
2x2=3
Step 1.2.5.2.2
Divide each term in 2x2=3 by 2 and simplify.
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Step 1.2.5.2.2.1
Divide each term in 2x2=3 by 2.
2x22=32
Step 1.2.5.2.2.2
Simplify the left side.
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Step 1.2.5.2.2.2.1
Cancel the common factor of 2.
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Step 1.2.5.2.2.2.1.1
Cancel the common factor.
2x22=32
Step 1.2.5.2.2.2.1.2
Divide x2 by 1.
x2=32
x2=32
x2=32
x2=32
Step 1.2.5.2.3
Take the specified root of both sides of the equation to eliminate the exponent on the left side.
x=±32
Step 1.2.5.2.4
Simplify ±32.
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Step 1.2.5.2.4.1
Rewrite 32 as 32.
x=±32
Step 1.2.5.2.4.2
Multiply 32 by 22.
x=±3222
Step 1.2.5.2.4.3
Combine and simplify the denominator.
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Step 1.2.5.2.4.3.1
Multiply 32 by 22.
x=±3222
Step 1.2.5.2.4.3.2
Raise 2 to the power of 1.
x=±32212
Step 1.2.5.2.4.3.3
Raise 2 to the power of 1.
x=±322121
Step 1.2.5.2.4.3.4
Use the power rule aman=am+n to combine exponents.
x=±3221+1
Step 1.2.5.2.4.3.5
Add 1 and 1.
x=±3222
Step 1.2.5.2.4.3.6
Rewrite 22 as 2.
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Step 1.2.5.2.4.3.6.1
Use nax=axn to rewrite 2 as 212.
x=±32(212)2
Step 1.2.5.2.4.3.6.2
Apply the power rule and multiply exponents, (am)n=amn.
x=±322122
Step 1.2.5.2.4.3.6.3
Combine 12 and 2.
x=±32222
Step 1.2.5.2.4.3.6.4
Cancel the common factor of 2.
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Step 1.2.5.2.4.3.6.4.1
Cancel the common factor.
x=±32222
Step 1.2.5.2.4.3.6.4.2
Rewrite the expression.
x=±3221
x=±3221
Step 1.2.5.2.4.3.6.5
Evaluate the exponent.
x=±322
x=±322
x=±322
Step 1.2.5.2.4.4
Simplify the numerator.
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Step 1.2.5.2.4.4.1
Combine using the product rule for radicals.
x=±322
Step 1.2.5.2.4.4.2
Multiply 3 by 2.
x=±62
x=±62
x=±62
Step 1.2.5.2.5
The complete solution is the result of both the positive and negative portions of the solution.
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Step 1.2.5.2.5.1
First, use the positive value of the ± to find the first solution.
x=62
Step 1.2.5.2.5.2
Next, use the negative value of the ± to find the second solution.
x=-62
Step 1.2.5.2.5.3
The complete solution is the result of both the positive and negative portions of the solution.
x=62,-62
x=62,-62
x=62,-62
x=62,-62
Step 1.2.6
The final solution is all the values that make 2x(2x2-3)=0 true.
x=0,62,-62
x=0,62,-62
Step 1.3
Find the values where the derivative is undefined.
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Step 1.3.1
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 1.4
Evaluate x4-3x2+4 at each x value where the derivative is 0 or undefined.
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Step 1.4.1
Evaluate at x=0.
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Step 1.4.1.1
Substitute 0 for x.
(0)4-3(0)2+4
Step 1.4.1.2
Simplify.
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Step 1.4.1.2.1
Simplify each term.
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Step 1.4.1.2.1.1
Raising 0 to any positive power yields 0.
0-3(0)2+4
Step 1.4.1.2.1.2
Raising 0 to any positive power yields 0.
0-30+4
Step 1.4.1.2.1.3
Multiply -3 by 0.
0+0+4
0+0+4
Step 1.4.1.2.2
Simplify by adding numbers.
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Step 1.4.1.2.2.1
Add 0 and 0.
0+4
Step 1.4.1.2.2.2
Add 0 and 4.
4
4
4
4
Step 1.4.2
Evaluate at x=62.
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Step 1.4.2.1
Substitute 62 for x.
(62)4-3(62)2+4
Step 1.4.2.2
Simplify.
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Step 1.4.2.2.1
Simplify each term.
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Step 1.4.2.2.1.1
Apply the product rule to 62.
6424-3(62)2+4
Step 1.4.2.2.1.2
Simplify the numerator.
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Step 1.4.2.2.1.2.1
Rewrite 64 as 62.
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Step 1.4.2.2.1.2.1.1
Use nax=axn to rewrite 6 as 612.
(612)424-3(62)2+4
Step 1.4.2.2.1.2.1.2
Apply the power rule and multiply exponents, (am)n=amn.
612424-3(62)2+4
Step 1.4.2.2.1.2.1.3
Combine 12 and 4.
64224-3(62)2+4
Step 1.4.2.2.1.2.1.4
Cancel the common factor of 4 and 2.
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Step 1.4.2.2.1.2.1.4.1
Factor 2 out of 4.
622224-3(62)2+4
Step 1.4.2.2.1.2.1.4.2
Cancel the common factors.
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Step 1.4.2.2.1.2.1.4.2.1
Factor 2 out of 2.
6222(1)24-3(62)2+4
Step 1.4.2.2.1.2.1.4.2.2
Cancel the common factor.
6222124-3(62)2+4
Step 1.4.2.2.1.2.1.4.2.3
Rewrite the expression.
62124-3(62)2+4
Step 1.4.2.2.1.2.1.4.2.4
Divide 2 by 1.
6224-3(62)2+4
6224-3(62)2+4
6224-3(62)2+4
6224-3(62)2+4
Step 1.4.2.2.1.2.2
Raise 6 to the power of 2.
3624-3(62)2+4
3624-3(62)2+4
Step 1.4.2.2.1.3
Raise 2 to the power of 4.
3616-3(62)2+4
Step 1.4.2.2.1.4
Cancel the common factor of 36 and 16.
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Step 1.4.2.2.1.4.1
Factor 4 out of 36.
4(9)16-3(62)2+4
Step 1.4.2.2.1.4.2
Cancel the common factors.
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Step 1.4.2.2.1.4.2.1
Factor 4 out of 16.
4944-3(62)2+4
Step 1.4.2.2.1.4.2.2
Cancel the common factor.
4944-3(62)2+4
Step 1.4.2.2.1.4.2.3
Rewrite the expression.
94-3(62)2+4
94-3(62)2+4
94-3(62)2+4
Step 1.4.2.2.1.5
Apply the product rule to 62.
94-36222+4
Step 1.4.2.2.1.6
Rewrite 62 as 6.
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Step 1.4.2.2.1.6.1
Use nax=axn to rewrite 6 as 612.
94-3(612)222+4
Step 1.4.2.2.1.6.2
Apply the power rule and multiply exponents, (am)n=amn.
94-3612222+4
Step 1.4.2.2.1.6.3
Combine 12 and 2.
94-362222+4
Step 1.4.2.2.1.6.4
Cancel the common factor of 2.
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Step 1.4.2.2.1.6.4.1
Cancel the common factor.
94-362222+4
Step 1.4.2.2.1.6.4.2
Rewrite the expression.
94-36122+4
94-36122+4
Step 1.4.2.2.1.6.5
Evaluate the exponent.
94-3622+4
94-3622+4
Step 1.4.2.2.1.7
Raise 2 to the power of 2.
94-3(64)+4
Step 1.4.2.2.1.8
Cancel the common factor of 6 and 4.
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Step 1.4.2.2.1.8.1
Factor 2 out of 6.
94-32(3)4+4
Step 1.4.2.2.1.8.2
Cancel the common factors.
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Step 1.4.2.2.1.8.2.1
Factor 2 out of 4.
94-32322+4
Step 1.4.2.2.1.8.2.2
Cancel the common factor.
94-32322+4
Step 1.4.2.2.1.8.2.3
Rewrite the expression.
94-3(32)+4
94-3(32)+4
94-3(32)+4
Step 1.4.2.2.1.9
Multiply -3(32).
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Step 1.4.2.2.1.9.1
Combine -3 and 32.
94+-332+4
Step 1.4.2.2.1.9.2
Multiply -3 by 3.
94+-92+4
94+-92+4
Step 1.4.2.2.1.10
Move the negative in front of the fraction.
94-92+4
94-92+4
Step 1.4.2.2.2
Find the common denominator.
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Step 1.4.2.2.2.1
Multiply 92 by 22.
94-(9222)+4
Step 1.4.2.2.2.2
Multiply 92 by 22.
94-9222+4
Step 1.4.2.2.2.3
Write 4 as a fraction with denominator 1.
94-9222+41
Step 1.4.2.2.2.4
Multiply 41 by 44.
94-9222+4144
Step 1.4.2.2.2.5
Multiply 41 by 44.
94-9222+444
Step 1.4.2.2.2.6
Multiply 2 by 2.
94-924+444
94-924+444
Step 1.4.2.2.3
Combine the numerators over the common denominator.
9-92+444
Step 1.4.2.2.4
Simplify each term.
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Step 1.4.2.2.4.1
Multiply -9 by 2.
9-18+444
Step 1.4.2.2.4.2
Multiply 4 by 4.
9-18+164
9-18+164
Step 1.4.2.2.5
Simplify by adding and subtracting.
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Step 1.4.2.2.5.1
Subtract 18 from 9.
-9+164
Step 1.4.2.2.5.2
Add -9 and 16.
74
74
74
74
Step 1.4.3
Evaluate at x=-62.
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Step 1.4.3.1
Substitute -62 for x.
(-62)4-3(-62)2+4
Step 1.4.3.2
Simplify.
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Step 1.4.3.2.1
Simplify each term.
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Step 1.4.3.2.1.1
Use the power rule (ab)n=anbn to distribute the exponent.
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Step 1.4.3.2.1.1.1
Apply the product rule to -62.
(-1)4(62)4-3(-62)2+4
Step 1.4.3.2.1.1.2
Apply the product rule to 62.
(-1)46424-3(-62)2+4
(-1)46424-3(-62)2+4
Step 1.4.3.2.1.2
Raise -1 to the power of 4.
16424-3(-62)2+4
Step 1.4.3.2.1.3
Multiply 6424 by 1.
6424-3(-62)2+4
Step 1.4.3.2.1.4
Simplify the numerator.
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Step 1.4.3.2.1.4.1
Rewrite 64 as 62.
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Step 1.4.3.2.1.4.1.1
Use nax=axn to rewrite 6 as 612.
(612)424-3(-62)2+4
Step 1.4.3.2.1.4.1.2
Apply the power rule and multiply exponents, (am)n=amn.
612424-3(-62)2+4
Step 1.4.3.2.1.4.1.3
Combine 12 and 4.
64224-3(-62)2+4
Step 1.4.3.2.1.4.1.4
Cancel the common factor of 4 and 2.
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Step 1.4.3.2.1.4.1.4.1
Factor 2 out of 4.
622224-3(-62)2+4
Step 1.4.3.2.1.4.1.4.2
Cancel the common factors.
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Step 1.4.3.2.1.4.1.4.2.1
Factor 2 out of 2.
6222(1)24-3(-62)2+4
Step 1.4.3.2.1.4.1.4.2.2
Cancel the common factor.
6222124-3(-62)2+4
Step 1.4.3.2.1.4.1.4.2.3
Rewrite the expression.
62124-3(-62)2+4
Step 1.4.3.2.1.4.1.4.2.4
Divide 2 by 1.
6224-3(-62)2+4
6224-3(-62)2+4
6224-3(-62)2+4
6224-3(-62)2+4
Step 1.4.3.2.1.4.2
Raise 6 to the power of 2.
3624-3(-62)2+4
3624-3(-62)2+4
Step 1.4.3.2.1.5
Raise 2 to the power of 4.
3616-3(-62)2+4
Step 1.4.3.2.1.6
Cancel the common factor of 36 and 16.
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Step 1.4.3.2.1.6.1
Factor 4 out of 36.
4(9)16-3(-62)2+4
Step 1.4.3.2.1.6.2
Cancel the common factors.
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Step 1.4.3.2.1.6.2.1
Factor 4 out of 16.
4944-3(-62)2+4
Step 1.4.3.2.1.6.2.2
Cancel the common factor.
4944-3(-62)2+4
Step 1.4.3.2.1.6.2.3
Rewrite the expression.
94-3(-62)2+4
94-3(-62)2+4
94-3(-62)2+4
Step 1.4.3.2.1.7
Use the power rule (ab)n=anbn to distribute the exponent.
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Step 1.4.3.2.1.7.1
Apply the product rule to -62.
94-3((-1)2(62)2)+4
Step 1.4.3.2.1.7.2
Apply the product rule to 62.
94-3((-1)26222)+4
94-3((-1)26222)+4
Step 1.4.3.2.1.8
Raise -1 to the power of 2.
94-3(16222)+4
Step 1.4.3.2.1.9
Multiply 6222 by 1.
94-36222+4
Step 1.4.3.2.1.10
Rewrite 62 as 6.
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Step 1.4.3.2.1.10.1
Use nax=axn to rewrite 6 as 612.
94-3(612)222+4
Step 1.4.3.2.1.10.2
Apply the power rule and multiply exponents, (am)n=amn.
94-3612222+4
Step 1.4.3.2.1.10.3
Combine 12 and 2.
94-362222+4
Step 1.4.3.2.1.10.4
Cancel the common factor of 2.
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Step 1.4.3.2.1.10.4.1
Cancel the common factor.
94-362222+4
Step 1.4.3.2.1.10.4.2
Rewrite the expression.
94-36122+4
94-36122+4
Step 1.4.3.2.1.10.5
Evaluate the exponent.
94-3622+4
94-3622+4
Step 1.4.3.2.1.11
Raise 2 to the power of 2.
94-3(64)+4
Step 1.4.3.2.1.12
Cancel the common factor of 6 and 4.
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Step 1.4.3.2.1.12.1
Factor 2 out of 6.
94-32(3)4+4
Step 1.4.3.2.1.12.2
Cancel the common factors.
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Step 1.4.3.2.1.12.2.1
Factor 2 out of 4.
94-32322+4
Step 1.4.3.2.1.12.2.2
Cancel the common factor.
94-32322+4
Step 1.4.3.2.1.12.2.3
Rewrite the expression.
94-3(32)+4
94-3(32)+4
94-3(32)+4
Step 1.4.3.2.1.13
Multiply -3(32).
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Step 1.4.3.2.1.13.1
Combine -3 and 32.
94+-332+4
Step 1.4.3.2.1.13.2
Multiply -3 by 3.
94+-92+4
94+-92+4
Step 1.4.3.2.1.14
Move the negative in front of the fraction.
94-92+4
94-92+4
Step 1.4.3.2.2
Find the common denominator.
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Step 1.4.3.2.2.1
Multiply 92 by 22.
94-(9222)+4
Step 1.4.3.2.2.2
Multiply 92 by 22.
94-9222+4
Step 1.4.3.2.2.3
Write 4 as a fraction with denominator 1.
94-9222+41
Step 1.4.3.2.2.4
Multiply 41 by 44.
94-9222+4144
Step 1.4.3.2.2.5
Multiply 41 by 44.
94-9222+444
Step 1.4.3.2.2.6
Multiply 2 by 2.
94-924+444
94-924+444
Step 1.4.3.2.3
Combine the numerators over the common denominator.
9-92+444
Step 1.4.3.2.4
Simplify each term.
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Step 1.4.3.2.4.1
Multiply -9 by 2.
9-18+444
Step 1.4.3.2.4.2
Multiply 4 by 4.
9-18+164
9-18+164
Step 1.4.3.2.5
Simplify by adding and subtracting.
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Step 1.4.3.2.5.1
Subtract 18 from 9.
-9+164
Step 1.4.3.2.5.2
Add -9 and 16.
74
74
74
74
Step 1.4.4
List all of the points.
(0,4),(62,74),(-62,74)
(0,4),(62,74),(-62,74)
(0,4),(62,74),(-62,74)
Step 2
Exclude the points that are not on the interval.
(0,4)
Step 3
Evaluate at the included endpoints.
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Step 3.1
Evaluate at x=-1.
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Step 3.1.1
Substitute -1 for x.
(-1)4-3(-1)2+4
Step 3.1.2
Simplify.
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Step 3.1.2.1
Simplify each term.
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Step 3.1.2.1.1
Raise -1 to the power of 4.
1-3(-1)2+4
Step 3.1.2.1.2
Raise -1 to the power of 2.
1-31+4
Step 3.1.2.1.3
Multiply -3 by 1.
1-3+4
1-3+4
Step 3.1.2.2
Simplify by adding and subtracting.
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Step 3.1.2.2.1
Subtract 3 from 1.
-2+4
Step 3.1.2.2.2
Add -2 and 4.
2
2
2
2
Step 3.2
Evaluate at x=1.
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Step 3.2.1
Substitute 1 for x.
(1)4-3(1)2+4
Step 3.2.2
Simplify.
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Step 3.2.2.1
Simplify each term.
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Step 3.2.2.1.1
One to any power is one.
1-3(1)2+4
Step 3.2.2.1.2
One to any power is one.
1-31+4
Step 3.2.2.1.3
Multiply -3 by 1.
1-3+4
1-3+4
Step 3.2.2.2
Simplify by adding and subtracting.
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Step 3.2.2.2.1
Subtract 3 from 1.
-2+4
Step 3.2.2.2.2
Add -2 and 4.
2
2
2
2
Step 3.3
List all of the points.
(-1,2),(1,2)
(-1,2),(1,2)
Step 4
Compare the f(x) values found for each value of x in order to determine the absolute maximum and minimum over the given interval. The maximum will occur at the highest f(x) value and the minimum will occur at the lowest f(x) value.
Absolute Maximum: (0,4)
Absolute Minimum: (-1,2),(1,2)
Step 5
 [x2  12  π  xdx ]