Given the directrix of y = 4 and focus of (0, 2), which is the equation of the parabola? y = one fourthx2 + 3 y = −one fourthx2 + 3 y = −one fourthx2 − 3 y = one fourthx2 − 3

y = - x² + 3

Step-by-step explanation:

Any point (x, y) on the parabola is equidistant from the focus and directrix.

Using the distance formula

= | y - 4 |, that is

= | y - 4 |

Squaring both sides

x² + (y - 2)² = (y - 4)² ← distribute parenthesis

x² + y² - 4y + 4 = y² - 8y + 16 ( subtract y² - 8y  from both sides )

x² + 4y + 4 = 16 ( subtract x² + 4 from both sides )

4y = - x² + 12 ( divide both sides by 4 )

y = - x² + 3

introduction, methodology, results, discussion

step-by-step explanation:

an observational study is one which consists of actual observation to record data and then analyse the data.

there are a number of factors that should be analyzed before starting an observational study.

the main four factors are:

i) introduction:   this should be analysed to check whether the purpose of the study is correctly established and the data recorded are appropriate for the study

methodology:   the method of collecting the data, such as whether randomly selected, and whether sample size matches with the population to be studied, whether questions asked are easy to answer by common men, etc.

results: then results such as summary of data with comments should be studied thoroughly

discussion:   the last is the discussion, this can be either by management people or persons who are all interested , etc.

the answer is; biodiversity resulting from few ancestors

adaptive radiation occurs when a population is subjected to a large natural environment with spatial ecological variations. the parts of the population in the different ecologies begin to adapt to their local environments. due to non-random mating across the large populations, this causes the different populations from the large population to speciate within their local environments. they, therefore, diverge to different species sharing a common ancestor.