Answer:
x = - 1 ± 2i
Step-by-step explanation:
we can use the discriminant b² - 4ac to determine the nature of the roots
• If b² - 4ac > , roots are real and distinct
• If b² - 4ac = 0, roots are real and equal
• If b² - ac < 0, roots are not real
for x² + 2x + 5 = 0
with a = 1, b = 2 and c = 5, then
b² - 4ac = 2² - (4 × 1 × 5 ) = 4 - 20 = - 16
since b² - 4ac < 0 there are 2 complex roots
using the quadratic formula to calculate the roots
x = ( - 2 ± 
) / 2
= (- 2 ± 4i ) / 2 = - 1 ± 2i
Answer:
19. 188
20. 18
21. 5
21. 4
Step-by-step explanation:
634.58 would round up to 635 and 436.79 would round up to 437.
20. 37.86 would round up to 38 and 19.92 would round up to 20.
21. 14.49 would round to 14 and 8.59 would round up to 9.
22. 7.45 would round down to 7 and 2.93 would round up to 3.
C. Lisa's lower pay was caused by babysitting for fewer hours
Step-by-step explanation:
cot < B = BC/AC = 7/24
_____
Answer:
We have in general that when a function has a high value, its reciprocal has a high value and vice-versa. That is the correlation between the function. When the function goes close to zero, it all depends on the sign. If the graph approaches 0 from positive values (for example sinx for small positive x), then we get that the reciprocal function is approaching infinity, namely high values of y. If this happens with negative values, we get that the y-values of the function approach minus infinity, namely they have very low y values. 1/sinx has such a point around x=0; for positive x it has very high values and for negative x it has very low values. It is breaking down at x=0 and it is not continuous.
Now, regarding how to teach it. The visual way is easy; one has to just find a simulation that makes the emphasis as the x value changes and shows us also what happens if we have a coefficient 7sinx and 1/(7sinx). If they have a more verbal approach to learning, it would make sense to focus on the inverse relationship between a function and its reciprocal... and also put emphasis on the importance of the sign of the function when the function is near 0. Logical mathematical approach: try to make calculations for large values of x and small values of x, introduce the concept of a limit of a function (Where its values tend to) or a function being continuous (smooth).
