Answer:
p(x) = - x³ + 2x² - 4x - 8
Step-by-step explanation:
Note that complex roots occur in conjugate pairs.
Given x = - 2i is a root then x = 2i is also a root
The roots of the polynomial are x = - 1, x = 2, x = - 2i and x = 2i
Thus the factors of the polynomial are
(x + 1), (x - 2), (x - 2i) and (x + 2i)
The polynomial is the product of it's roots, thus
p(x) = (x + 1)(x - 2)(x - 2i)(x + 2i) ← expand in pairs
= (x² - x - 2)(x² - 4i²) → note i² = - 1, so
= (x² - x - 2)(x² + 4) ← distribute parenthesis
= + 4x² - x³ - 4x - 2x² - 8 ← collect like terms
= - x³ + 2x² - 4x - 8
Answer:
33 m/s
Step-by-step explanation:
120 km/h × (1 h)/(3600 s) × (1000 m)/(1 km) ≈ 33 m/s
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<em>Additional comment</em>
In general, units conversion is done by multiplying by a factor whose numerator and denominator have equal values, but different units. The units in that fraction need to be arranged to cancel the units you don't want and leave the units you do want.
Answer:
i could be wrong but i think its x=3 :(
Step-by-step explanation:
Answer:
Step-by-step explanation:
income elasticity of demand for the good X = % change in quantity demanded / % change in income of consumer = - 15 / 2 = - 7.50 negative since it is a decrease in demand.
and the good X is an inferior good since increase income brings about a decrease in quantity demanded of the goods compared to normal good where a decrease in income brings about decrease in quantity demanded and an increase in income brings about increase in quantity demanded.