Question

Find the value of

$5 {x}^{4} + 3 {x}^{3} + 7 {x}^{2} - x + 12$
when

$x = - 2 - \sqrt{3} i$
​

Answer 1

Step-by-step explanation:

x = -2-√3i

x² = (2+√3i)² = (1 + 4√3i)

x^3 = (1+4√3i)(-2-√3i)

= (-2-√3i --8√3i +12)

= (10 - 9√3 i)

x^4 = (1 + 4√3i)²

= (1 - 48 +8√3 i)

= (-47 + 8√3 i)

5x^4 + 3x^3 + 7x² - x + 12

= 5(-47 + 8√3 i) + 3(10 - 9√3 i) + 7(1 + 4√3i ) - ( -2-√3i)+12

= -235 + 40√3i + 30 -27√3i +7+28√3i +2+√3i +12

= -184 + 42√3i

Answer 2

Answer:

the process by which green plants turn carbon dioxide and water into food using energy from sunlight