in short, you simply pick a few random "x" values, to get the "y", and that's your point, for example say x = 2, then y = -(2)² - 4 => y = -8, that gives us the point of (2, -8), and so on.
we can start off by finding the vertex, the U-turn of the graph, and then just pick a point to its left side and a point to its right side, and we can get the vertex of that by
![\bf y=-4x^2-4\implies y=-4x^2+0x-4 \\\\[-0.35em] ~\dotfill\\\\ \textit{vertex of a vertical parabola, using coefficients} \\\\ y=\stackrel{\stackrel{a}{\downarrow }}{-4}x^2\stackrel{\stackrel{b}{\downarrow }}{+0}x\stackrel{\stackrel{c}{\downarrow }}{-4} \qquad \qquad \left(-\cfrac{ b}{2 a}~~~~ ,~~~~ c-\cfrac{ b^2}{4 a}\right) \\\\\\ \left(-\cfrac{0}{2(-4)}~,~-4-\cfrac{0}{4(-4)} \right)\implies (0~,~-4-0)\implies (0,-4)](https://tex.z-dn.net/?f=%5Cbf%20y%3D-4x%5E2-4%5Cimplies%20y%3D-4x%5E2%2B0x-4%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20%5Ctextit%7Bvertex%20of%20a%20vertical%20parabola%2C%20using%20coefficients%7D%20%5C%5C%5C%5C%20y%3D%5Cstackrel%7B%5Cstackrel%7Ba%7D%7B%5Cdownarrow%20%7D%7D%7B-4%7Dx%5E2%5Cstackrel%7B%5Cstackrel%7Bb%7D%7B%5Cdownarrow%20%7D%7D%7B%2B0%7Dx%5Cstackrel%7B%5Cstackrel%7Bc%7D%7B%5Cdownarrow%20%7D%7D%7B-4%7D%20%5Cqquad%20%5Cqquad%20%5Cleft%28-%5Ccfrac%7B%20b%7D%7B2%20a%7D~~~~%20%2C~~~~%20c-%5Ccfrac%7B%20b%5E2%7D%7B4%20a%7D%5Cright%29%20%5C%5C%5C%5C%5C%5C%20%5Cleft%28-%5Ccfrac%7B0%7D%7B2%28-4%29%7D~%2C~-4-%5Ccfrac%7B0%7D%7B4%28-4%29%7D%20%5Cright%29%5Cimplies%20%280~%2C~-4-0%29%5Cimplies%20%280%2C-4%29)
and since it's a vertical parabola, the axis of symmetry comes from the x-coordinate of the vertex, namely x = 0, check the picture below.
Answer:
20:40
Step-by-step explanation:
Because part of the ratio is the total number of berries, we need to add up all of the berries.
20+15+5=40
The number of strawberries picked is 20, so the ratio is 20:40
Answer: 2.8%
Step-by-step explanation:
Give, In a certain month a family spent $750 on food
In third month the family spent $729 on food .
i.e. Expenditure on food in a certain month = $750
Expenditure on food in third month = $729
Decrease in monthly spending on food = (Expenditure in a certain month )- (Expenditure in third month )
= $750 - $729
= $21
Now , the percentage decrease in the month spent on food will be :
Hence, the percentage decrease in the month spent on food is 2.8%.
It is given in the question that
Jess has dinner at a restaurant. The dinner bill is B dollars. She pays a 21% tip.
THerefore,
Jess's bill amount without tip is $ B.
Jess's tip amount is 21 % of B or 0.21B
THerefore Jess's total amount is the sum of Jess's bill amount without tip and Jess's tip amount, that is
Hence, Jess's total amount is 1.21B .
