Linear Algebra Examples
⎡⎢⎣−143112−10−1⎤⎥⎦
Step 1
Set up the formula to find the characteristic equation p(λ).
p(λ)=determinant(A−λI3)
Step 2
The identity matrix or unit matrix of size 3 is the 3×3 square matrix with ones on the main diagonal and zeros elsewhere.
⎡⎢⎣100010001⎤⎥⎦
Step 3
Step 3.1
Substitute ⎡⎢⎣−143112−10−1⎤⎥⎦ for A.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦−λI3⎞⎟⎠
Step 3.2
Substitute ⎡⎢⎣100010001⎤⎥⎦ for I3.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦−λ⎡⎢⎣100010001⎤⎥⎦⎞⎟⎠
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦−λ⎡⎢⎣100010001⎤⎥⎦⎞⎟⎠
Step 4
Step 4.1
Simplify each term.
Step 4.1.1
Multiply −λ by each element of the matrix.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ⋅1−λ⋅0−λ⋅0−λ⋅0−λ⋅1−λ⋅0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2
Simplify each element in the matrix.
Step 4.1.2.1
Multiply −1 by 1.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ−λ⋅0−λ⋅0−λ⋅0−λ⋅1−λ⋅0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.2
Multiply −λ⋅0.
Step 4.1.2.2.1
Multiply 0 by −1.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ0λ−λ⋅0−λ⋅0−λ⋅1−λ⋅0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.2.2
Multiply 0 by λ.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ0−λ⋅0−λ⋅0−λ⋅1−λ⋅0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ0−λ⋅0−λ⋅0−λ⋅1−λ⋅0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.3
Multiply −λ⋅0.
Step 4.1.2.3.1
Multiply 0 by −1.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ00λ−λ⋅0−λ⋅1−λ⋅0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.3.2
Multiply 0 by λ.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ00−λ⋅0−λ⋅1−λ⋅0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ00−λ⋅0−λ⋅1−λ⋅0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.4
Multiply −λ⋅0.
Step 4.1.2.4.1
Multiply 0 by −1.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000λ−λ⋅1−λ⋅0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.4.2
Multiply 0 by λ.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ⋅1−λ⋅0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ⋅1−λ⋅0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.5
Multiply −1 by 1.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ−λ⋅0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.6
Multiply −λ⋅0.
Step 4.1.2.6.1
Multiply 0 by −1.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ0λ−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.6.2
Multiply 0 by λ.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ0−λ⋅0−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.7
Multiply −λ⋅0.
Step 4.1.2.7.1
Multiply 0 by −1.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ00λ−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.7.2
Multiply 0 by λ.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ00−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ00−λ⋅0−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.8
Multiply −λ⋅0.
Step 4.1.2.8.1
Multiply 0 by −1.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ000λ−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.8.2
Multiply 0 by λ.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ000−λ⋅1⎤⎥⎦⎞⎟⎠
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ000−λ⋅1⎤⎥⎦⎞⎟⎠
Step 4.1.2.9
Multiply −1 by 1.
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ000−λ⎤⎥⎦⎞⎟⎠
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ000−λ⎤⎥⎦⎞⎟⎠
p(λ)=determinant⎛⎜⎝⎡⎢⎣−143112−10−1⎤⎥⎦+⎡⎢⎣−λ000−λ000−λ⎤⎥⎦⎞⎟⎠
Step 4.2
Add the corresponding elements.
p(λ)=determinant⎡⎢⎣−1−λ4+03+01+01−λ2+0−1+00+0−1−λ⎤⎥⎦
Step 4.3
Simplify each element.
Step 4.3.1
Add 4 and 0.
p(λ)=determinant⎡⎢⎣−1−λ43+01+01−λ2+0−1+00+0−1−λ⎤⎥⎦
Step 4.3.2
Add 3 and 0.
p(λ)=determinant⎡⎢⎣−1−λ431+01−λ2+0−1+00+0−1−λ⎤⎥⎦
Step 4.3.3
Add 1 and 0.
p(λ)=determinant⎡⎢⎣−1−λ4311−λ2+0−1+00+0−1−λ⎤⎥⎦
Step 4.3.4
Add 2 and 0.
p(λ)=determinant⎡⎢⎣−1−λ4311−λ2−1+00+0−1−λ⎤⎥⎦
Step 4.3.5
Add −1 and 0.
p(λ)=determinant⎡⎢⎣−1−λ4311−λ2−10+0−1−λ⎤⎥⎦
Step 4.3.6
Add 0 and 0.
p(λ)=determinant⎡⎢⎣−1−λ4311−λ2−10−1−λ⎤⎥⎦
p(λ)=determinant⎡⎢⎣−1−λ4311−λ2−10−1−λ⎤⎥⎦
p(λ)=determinant⎡⎢⎣−1−λ4311−λ2−10−1−λ⎤⎥⎦
Step 5
Step 5.1
Choose the row or column with the most 0 elements. If there are no 0 elements choose any row or column. Multiply every element in column 2 by its cofactor and add.
Step 5.1.1
Consider the corresponding sign chart.
∣∣
∣∣+−+−+−+−+∣∣
∣∣
Step 5.1.2
The cofactor is the minor with the sign changed if the indices match a − position on the sign chart.
Step 5.1.3
The minor for a12 is the determinant with row 1 and column 2 deleted.
∣∣∣12−1−1−λ∣∣∣
Step 5.1.4
Multiply element a12 by its cofactor.
−4∣∣∣12−1−1−λ∣∣∣
Step 5.1.5
The minor for a22 is the determinant with row 2 and column 2 deleted.
∣∣∣−1−λ3−1−1−λ∣∣∣
Step 5.1.6
Multiply element a22 by its cofactor.
(1−λ)∣∣∣−1−λ3−1−1−λ∣∣∣
Step 5.1.7
The minor for a32 is the determinant with row 3 and column 2 deleted.
∣∣∣−1−λ312∣∣∣
Step 5.1.8
Multiply element a32 by its cofactor.
0∣∣∣−1−λ312∣∣∣
Step 5.1.9
Add the terms together.
p(λ)=−4∣∣∣12−1−1−λ∣∣∣+(1−λ)∣∣∣−1−λ3−1−1−λ∣∣∣+0∣∣∣−1−λ312∣∣∣
p(λ)=−4∣∣∣12−1−1−λ∣∣∣+(1−λ)∣∣∣−1−λ3−1−1−λ∣∣∣+0∣∣∣−1−λ312∣∣∣
Step 5.2
Multiply 0 by ∣∣∣−1−λ312∣∣∣.
p(λ)=−4∣∣∣12−1−1−λ∣∣∣+(1−λ)∣∣∣−1−λ3−1−1−λ∣∣∣+0
Step 5.3
Evaluate ∣∣∣12−1−1−λ∣∣∣.
Step 5.3.1
The determinant of a 2×2 matrix can be found using the formula ∣∣∣abcd∣∣∣=ad−cb.
p(λ)=−4(1(−1−λ)−(−1⋅2))+(1−λ)∣∣∣−1−λ3−1−1−λ∣∣∣+0
Step 5.3.2
Simplify the determinant.
Step 5.3.2.1
Simplify each term.
Step 5.3.2.1.1
Multiply −1−λ by 1.
p(λ)=−4(−1−λ−(−1⋅2))+(1−λ)∣∣∣−1−λ3−1−1−λ∣∣∣+0
Step 5.3.2.1.2
Multiply −(−1⋅2).
Step 5.3.2.1.2.1
Multiply −1 by 2.
p(λ)=−4(−1−λ−−2)+(1−λ)∣∣∣−1−λ3−1−1−λ∣∣∣+0
Step 5.3.2.1.2.2
Multiply −1 by −2.
p(λ)=−4(−1−λ+2)+(1−λ)∣∣∣−1−λ3−1−1−λ∣∣∣+0
p(λ)=−4(−1−λ+2)+(1−λ)∣∣∣−1−λ3−1−1−λ∣∣∣+0
p(λ)=−4(−1−λ+2)+(1−λ)∣∣∣−1−λ3−1−1−λ∣∣∣+0
Step 5.3.2.2
Add −1 and 2.
p(λ)=−4(−λ+1)+(1−λ)∣∣∣−1−λ3−1−1−λ∣∣∣+0
p(λ)=−4(−λ+1)+(1−λ)∣∣∣−1−λ3−1−1−λ∣∣∣+0
p(λ)=−4(−λ+1)+(1−λ)∣∣∣−1−λ3−1−1−λ∣∣∣+0
Step 5.4
Evaluate ∣∣∣−1−λ3−1−1−λ∣∣∣.
Step 5.4.1
The determinant of a 2×2 matrix can be found using the formula ∣∣∣abcd∣∣∣=ad−cb.
p(λ)=−4(−λ+1)+(1−λ)((−1−λ)(−1−λ)−(−1⋅3))+0
Step 5.4.2
Simplify the determinant.
Step 5.4.2.1
Simplify each term.
Step 5.4.2.1.1
Expand (−1−λ)(−1−λ) using the FOIL Method.
Step 5.4.2.1.1.1
Apply the distributive property.
p(λ)=−4(−λ+1)+(1−λ)(−1(−1−λ)−λ(−1−λ)−(−1⋅3))+0
Step 5.4.2.1.1.2
Apply the distributive property.
p(λ)=−4(−λ+1)+(1−λ)(−1⋅−1−1(−λ)−λ(−1−λ)−(−1⋅3))+0
Step 5.4.2.1.1.3
Apply the distributive property.
p(λ)=−4(−λ+1)+(1−λ)(−1⋅−1−1(−λ)−λ⋅−1−λ(−λ)−(−1⋅3))+0
p(λ)=−4(−λ+1)+(1−λ)(−1⋅−1−1(−λ)−λ⋅−1−λ(−λ)−(−1⋅3))+0
Step 5.4.2.1.2
Simplify and combine like terms.
Step 5.4.2.1.2.1
Simplify each term.
Step 5.4.2.1.2.1.1
Multiply −1 by −1.
p(λ)=−4(−λ+1)+(1−λ)(1−1(−λ)−λ⋅−1−λ(−λ)−(−1⋅3))+0
Step 5.4.2.1.2.1.2
Multiply −1(−λ).
Step 5.4.2.1.2.1.2.1
Multiply −1 by −1.
p(λ)=−4(−λ+1)+(1−λ)(1+1λ−λ⋅−1−λ(−λ)−(−1⋅3))+0
Step 5.4.2.1.2.1.2.2
Multiply λ by 1.
p(λ)=−4(−λ+1)+(1−λ)(1+λ−λ⋅−1−λ(−λ)−(−1⋅3))+0
p(λ)=−4(−λ+1)+(1−λ)(1+λ−λ⋅−1−λ(−λ)−(−1⋅3))+0
Step 5.4.2.1.2.1.3
Multiply −λ⋅−1.
Step 5.4.2.1.2.1.3.1
Multiply −1 by −1.
p(λ)=−4(−λ+1)+(1−λ)(1+λ+1λ−λ(−λ)−(−1⋅3))+0
Step 5.4.2.1.2.1.3.2
Multiply λ by 1.
p(λ)=−4(−λ+1)+(1−λ)(1+λ+λ−λ(−λ)−(−1⋅3))+0
p(λ)=−4(−λ+1)+(1−λ)(1+λ+λ−λ(−λ)−(−1⋅3))+0
Step 5.4.2.1.2.1.4
Rewrite using the commutative property of multiplication.
p(λ)=−4(−λ+1)+(1−λ)(1+λ+λ−1⋅−1λ⋅λ−(−1⋅3))+0
Step 5.4.2.1.2.1.5
Multiply λ by λ by adding the exponents.
Step 5.4.2.1.2.1.5.1
Move λ.
p(λ)=−4(−λ+1)+(1−λ)(1+λ+λ−1⋅−1(λ⋅λ)−(−1⋅3))+0
Step 5.4.2.1.2.1.5.2
Multiply λ by λ.
p(λ)=−4(−λ+1)+(1−λ)(1+λ+λ−1⋅−1λ2−(−1⋅3))+0
p(λ)=−4(−λ+1)+(1−λ)(1+λ+λ−1⋅−1λ2−(−1⋅3))+0
Step 5.4.2.1.2.1.6
Multiply −1 by −1.
p(λ)=−4(−λ+1)+(1−λ)(1+λ+λ+1λ2−(−1⋅3))+0
Step 5.4.2.1.2.1.7
Multiply λ2 by 1.
p(λ)=−4(−λ+1)+(1−λ)(1+λ+λ+λ2−(−1⋅3))+0
p(λ)=−4(−λ+1)+(1−λ)(1+λ+λ+λ2−(−1⋅3))+0
Step 5.4.2.1.2.2
Add λ and λ.
p(λ)=−4(−λ+1)+(1−λ)(1+2λ+λ2−(−1⋅3))+0
p(λ)=−4(−λ+1)+(1−λ)(1+2λ+λ2−(−1⋅3))+0
Step 5.4.2.1.3
Multiply −(−1⋅3).
Step 5.4.2.1.3.1
Multiply −1 by 3.
p(λ)=−4(−λ+1)+(1−λ)(1+2λ+λ2−−3)+0
Step 5.4.2.1.3.2
Multiply −1 by −3.
p(λ)=−4(−λ+1)+(1−λ)(1+2λ+λ2+3)+0
p(λ)=−4(−λ+1)+(1−λ)(1+2λ+λ2+3)+0
p(λ)=−4(−λ+1)+(1−λ)(1+2λ+λ2+3)+0
Step 5.4.2.2
Add 1 and 3.
p(λ)=−4(−λ+1)+(1−λ)(2λ+λ2+4)+0
Step 5.4.2.3
Reorder 2λ and λ2.
p(λ)=−4(−λ+1)+(1−λ)(λ2+2λ+4)+0
p(λ)=−4(−λ+1)+(1−λ)(λ2+2λ+4)+0
p(λ)=−4(−λ+1)+(1−λ)(λ2+2λ+4)+0
Step 5.5
Simplify the determinant.
Step 5.5.1
Add −4(−λ+1)+(1−λ)(λ2+2λ+4) and 0.
p(λ)=−4(−λ+1)+(1−λ)(λ2+2λ+4)
Step 5.5.2
Simplify each term.
Step 5.5.2.1
Apply the distributive property.
p(λ)=−4(−λ)−4⋅1+(1−λ)(λ2+2λ+4)
Step 5.5.2.2
Multiply −1 by −4.
p(λ)=4λ−4⋅1+(1−λ)(λ2+2λ+4)
Step 5.5.2.3
Multiply −4 by 1.
p(λ)=4λ−4+(1−λ)(λ2+2λ+4)
Step 5.5.2.4
Expand (1−λ)(λ2+2λ+4) by multiplying each term in the first expression by each term in the second expression.
p(λ)=4λ−4+1λ2+1(2λ)+1⋅4−λ⋅λ2−λ(2λ)−λ⋅4
Step 5.5.2.5
Simplify each term.
Step 5.5.2.5.1
Multiply λ2 by 1.
p(λ)=4λ−4+λ2+1(2λ)+1⋅4−λ⋅λ2−λ(2λ)−λ⋅4
Step 5.5.2.5.2
Multiply 2λ by 1.
p(λ)=4λ−4+λ2+2λ+1⋅4−λ⋅λ2−λ(2λ)−λ⋅4
Step 5.5.2.5.3
Multiply 4 by 1.
p(λ)=4λ−4+λ2+2λ+4−λ⋅λ2−λ(2λ)−λ⋅4
Step 5.5.2.5.4
Multiply λ by λ2 by adding the exponents.
Step 5.5.2.5.4.1
Move λ2.
p(λ)=4λ−4+λ2+2λ+4−(λ2λ)−λ(2λ)−λ⋅4
Step 5.5.2.5.4.2
Multiply λ2 by λ.
Step 5.5.2.5.4.2.1
Raise λ to the power of 1.
p(λ)=4λ−4+λ2+2λ+4−(λ2λ1)−λ(2λ)−λ⋅4
Step 5.5.2.5.4.2.2
Use the power rule aman=am+n to combine exponents.
p(λ)=4λ−4+λ2+2λ+4−λ2+1−λ(2λ)−λ⋅4
p(λ)=4λ−4+λ2+2λ+4−λ2+1−λ(2λ)−λ⋅4
Step 5.5.2.5.4.3
Add 2 and 1.
p(λ)=4λ−4+λ2+2λ+4−λ3−λ(2λ)−λ⋅4
p(λ)=4λ−4+λ2+2λ+4−λ3−λ(2λ)−λ⋅4
Step 5.5.2.5.5
Rewrite using the commutative property of multiplication.
p(λ)=4λ−4+λ2+2λ+4−λ3−1⋅2λ⋅λ−λ⋅4
Step 5.5.2.5.6
Multiply λ by λ by adding the exponents.
Step 5.5.2.5.6.1
Move λ.
p(λ)=4λ−4+λ2+2λ+4−λ3−1⋅2(λ⋅λ)−λ⋅4
Step 5.5.2.5.6.2
Multiply λ by λ.
p(λ)=4λ−4+λ2+2λ+4−λ3−1⋅2λ2−λ⋅4
p(λ)=4λ−4+λ2+2λ+4−λ3−1⋅2λ2−λ⋅4
Step 5.5.2.5.7
Multiply −1 by 2.
p(λ)=4λ−4+λ2+2λ+4−λ3−2λ2−λ⋅4
Step 5.5.2.5.8
Multiply 4 by −1.
p(λ)=4λ−4+λ2+2λ+4−λ3−2λ2−4λ
p(λ)=4λ−4+λ2+2λ+4−λ3−2λ2−4λ
Step 5.5.2.6
Subtract 2λ2 from λ2.
p(λ)=4λ−4−λ2+2λ+4−λ3−4λ
Step 5.5.2.7
Subtract 4λ from 2λ.
p(λ)=4λ−4−λ2−2λ+4−λ3
p(λ)=4λ−4−λ2−2λ+4−λ3
Step 5.5.3
Combine the opposite terms in 4λ−4−λ2−2λ+4−λ3.
Step 5.5.3.1
Add −4 and 4.
p(λ)=4λ−λ2−2λ+0−λ3
Step 5.5.3.2
Add 4λ−λ2−2λ and 0.
p(λ)=4λ−λ2−2λ−λ3
p(λ)=4λ−λ2−2λ−λ3
Step 5.5.4
Subtract 2λ from 4λ.
p(λ)=−λ2+2λ−λ3
Step 5.5.5
Move 2λ.
p(λ)=−λ2−λ3+2λ
Step 5.5.6
Reorder −λ2 and −λ3.
p(λ)=−λ3−λ2+2λ
p(λ)=−λ3−λ2+2λ
p(λ)=−λ3−λ2+2λ
Step 6
Set the characteristic polynomial equal to 0 to find the eigenvalues λ.
−λ3−λ2+2λ=0
Step 7
Step 7.1
Factor the left side of the equation.
Step 7.1.1
Factor −λ out of −λ3−λ2+2λ.
Step 7.1.1.1
Factor −λ out of −λ3.
−λ⋅λ2−λ2+2λ=0
Step 7.1.1.2
Factor −λ out of −λ2.
−λ⋅λ2−λ⋅λ+2λ=0
Step 7.1.1.3
Factor −λ out of 2λ.
−λ⋅λ2−λ⋅λ−λ⋅−2=0
Step 7.1.1.4
Factor −λ out of −λ(λ2)−λ(λ).
−λ(λ2+λ)−λ⋅−2=0
Step 7.1.1.5
Factor −λ out of −λ(λ2+λ)−λ(−2).
−λ(λ2+λ−2)=0
−λ(λ2+λ−2)=0
Step 7.1.2
Factor.
Step 7.1.2.1
Factor λ2+λ−2 using the AC method.
Step 7.1.2.1.1
Consider the form x2+bx+c. Find a pair of integers whose product is c and whose sum is b. In this case, whose product is −2 and whose sum is 1.
−1,2
Step 7.1.2.1.2
Write the factored form using these integers.
−λ((λ−1)(λ+2))=0
−λ((λ−1)(λ+2))=0
Step 7.1.2.2
Remove unnecessary parentheses.
−λ(λ−1)(λ+2)=0
−λ(λ−1)(λ+2)=0
−λ(λ−1)(λ+2)=0
Step 7.2
If any individual factor on the left side of the equation is equal to 0, the entire expression will be equal to 0.
λ=0
λ−1=0
λ+2=0
Step 7.3
Set λ equal to 0.
λ=0
Step 7.4
Set λ−1 equal to 0 and solve for λ.
Step 7.4.1
Set λ−1 equal to 0.
λ−1=0
Step 7.4.2
Add 1 to both sides of the equation.
λ=1
λ=1
Step 7.5
Set λ+2 equal to 0 and solve for λ.
Step 7.5.1
Set λ+2 equal to 0.
λ+2=0
Step 7.5.2
Subtract 2 from both sides of the equation.
λ=−2
λ=−2
Step 7.6
The final solution is all the values that make −λ(λ−1)(λ+2)=0 true.
λ=0,1,−2
λ=0,1,−2