9. negative 10. negative 11. negative 12.negative 13.negative 14. positive 15. positive 16. negative 17. negative 18. positive
Answer: a) √50
b) n = 1 + 7i
Step-by-step explanation:
first, the modulus of a complex number z = a + bi is
IzI = √(a^2 + b^2)
The fact that n is complex does not mean that n doesn't has a real part, so we must write our numbers as:
m = 2 + 6i
n = a + bi
Im + nI = 3√10
Im + n I = √(a^2 + b^2 + 2^2 + 6^2)= 3√10
= √(a^2 + b^2 + 40) = 3√10
a^2 + b^2 + 40 = 3^2*10 = 9*10 = 90
a^2 + b^2 = 90 - 40 = 50
√(a^2 + b^2 ) = InI = √50
The modulus of n must be equal to the square root of 50.
now we can find any values a and b such a^2 + b^2 = 50.
for example, a = 1 and b = 7
1^2 + 7^2 = 1 + 49 = 50
Then a possible value for n is:
n = 1 + 7i
Volume of a cone = 1/3 π r² h
235.5 = 1/3 (3.14) r² (9)
(3.14) r² (9) = 706.5
r² = 25
r = 5
Answer: Radius = 5 cm
Since 12 is hypotenuse, formula we would use is:
12^2=5^2+x^2
144=25+x^2
x^2= 144-25
x^2=119
x= √119
x=10.9087
Rounded to nearest tenth,
x=10.9
Good luck.