Question

find the cubic equation two of whose roots are 1-i and 5

Answer 1

Answer:

• x³ - x² + x - 1 = 0

Step-by-step explanation:

Question,

Find the cubic equation whose roots are 1,i.

Solution,

If i is one root, the other root will be -i

So, the roots are:-

• 1
• i
• -1

So, the equation will be,

=> (x - 1)(x + i)(x - i) = 0

=> (x - 1)(x² - i²) = 0

=> x³ + x - x² - 1 = 0

∴ x³ - x² + x - 1 = 0