x⁴-5x³+8x²-5x+1=0 find the roots
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Step-by-step explanation:
Solve for x:
x^4 - 5 x^3 + 8 x^2 - 5 x + 1 = 0
The left hand side factors into a product with two terms:
(x - 1)^2 (x^2 - 3 x + 1) = 0
Split into two equations:
(x - 1)^2 = 0 or x^2 - 3 x + 1 = 0
Take the square root of both sides:
x - 1 = 0 or x^2 - 3 x + 1 = 0
Add 1 to both sides:
x = 1 or x^2 - 3 x + 1 = 0
Subtract 1 from both sides:
x = 1 or x^2 - 3 x = -1
Add 9/4 to both sides:
x = 1 or x^2 - 3 x + 9/4 = 5/4
Write the left hand side as a square:
x = 1 or (x - 3/2)^2 = 5/4
Take the square root of both sides:
x = 1 or x - 3/2 = sqrt(5)/2 or x - 3/2 = -sqrt(5)/2
Add 3/2 to both sides:
x = 1 or x = 3/2 + sqrt(5)/2 or x - 3/2 = -sqrt(5)/2
Add 3/2 to both sides:
Answer: |
| x = 1 or x = 3/2 + sqrt(5)/2 or x = 3/2 - sqrt(5)/2
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