Here i how I would do it:<span>f(x)=−<span>x2</span>+8x+15</span>
set f(x) = 0 to find the points at which the graph crosses the x-axis. So<span>−<span>x2</span>+8x+15=0</span>
multiply through by -1<span><span>x2</span>−8x−15=0</span>
<span>(x−4<span>)2</span>−31=0</span>
<span>x=4±<span>31<span>−−</span>√</span></span>
So these are the points at which the graph crosses the x-axis. To find the point where it crosses the y-axis, set x=0 in your original equation to get 15. Now because of the negative on the x^2, your graph will be an upside down parabola, going through<span>(0,15),(4−<span>31<span>−−</span>√</span>,0)and(4+<span>31<span>−−</span>√</span>,0)</span>
To find the coordinates of the maximum (it is maximum) of the graph, you take a look at the completed square method above. Since we multiplied through by -1, we need to multiply through by it again to get:<span>f(x)=31−(x−4<span>)2</span></span><span>
Now this is maximal when x=4, because x=4 causes -(x-4)^2 to vanish. So the coordinates of the maximum are (4,y). To find the y, simply substitute x=4 into the equation f(x) to give y = 31. So it agrees with the mighty Satellite: (4,31) is the vertex.</span>
2 1/10 because the 1 in 2.1 is in the tenth place
Answer:
$1,131.20 is the amount earned
Step-by-step explanation:
<u>Key skills needed: Simple Interest Formula, Operations ( +, - , x , / )</u>
1) To understand this problem, you need to know the simple interest formula.
A = P(1+rt)
A is the amount
P is the principal
R is the interest rate as a decimal
T is the time in years
2) The 1st thing we need to do is convert the interest rate into a decimal. We have 14%. To convert into decimal form, we divide it by a 100, or move the decimal 2 places to the left. This is 0.14 --> So r=0.14
3) Next we use the formula:
A = 1,010(1+ 0.14(8))
- We first do 0.14(8) which is 1.12 and then add it to the 1 value, so you will get --> A = 1,010(2.12)
- Multiply and you will get A = $2,141.20
- To find the interest earned, you subtract this by the original amount, so $2,141.20 - $1,010 which would be $1,131.20
This means $1,131.20 is your answer.
<em>Hope you understood and have a nice day!! :D</em>
Answer:
Step-by-step explanation:
the diameter is the measurement that is all the way across the circle which is given to you so the diameter is 7cm. To find the radius it is half the way across the circle so it is half the diameter so in this case the radius would be 3.5cm
Answer:
Step-by-step explanation:
Could you confirm to me that this is in fact the problem? Do not report. I will edit this answer once you answer my question.
