Answer:
Every week, the radioactivity decreases by a factor of 5
After 1 week, it goes from 5,000 to 1,000
2 weeks 1,000 / 5 =200
3 weeks 200 / 5 = 40
4 weeks 40 / 5 = 8
5 weeks 8 / 5 = 1.6
6 weeks 1.6 / 5 = 0.064
7 weeks 0.064 / 5 = 0.0128
8 weeks .0128 / 5 = 0.00256
9 weeks 0.00256 / 5 = 0.000512
10 weeks 0.000512 / 5 = 0.0001024
Step-by-step explanation:
To get the vertex of the parabola we proceed as follows;
y=-7(x-4)^2-5
The above can be written as:
y=-7x^2+56x-117
The values of a,b and c are:
a=-7, b=56 and c=-117
x=-b/(2a)
x=-56/(-7*2)=4
but;
y=-7x^2+56x-117
y=-7(4)^2+56(4)-117
y=-5
Thus;
x=4 and y=-5
The vertex will be at point (4,-5)
Answer:
Step-by-step explanation:
#22
<h3>Given </h3>
- Equation x² -4x + 1 = k(x - 4) with equal roots
<h3>To find</h3>
<h3>Solution</h3>
<u>The equation in standard form is:</u>
- x² -4x + 1 = k(x - 4)
- x² - 4x - kx + 1 + 4 = 0
- x² - (k + 4)x + 5 = 0
<u>When the quadratic equation has equal roots its discriminant is zero</u>
- D = 0
- b² - 4ac = 0
- (k + 4)² - 4*5 = 0
- (k + 4)² = 20
- k + 4 = ± √20
- k = - 4 ± √20
- or
- k = -4 ± 2√5
83-63=20
So your answer is 20
Does radical mean square root?, because radical can mean square root, cube root, fourth root, etc.
Well, I'm going to assume that radical = square root
So, if you have two square root functions, you can multiply the numbers within the square root, so you now have 
, which I'm not sure if you want it simplified or not
