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>
Answer:
7
Step-by-step explanation:
Since, Sophia had three pages of homework and she only has three left you can set up an equation to solve. The equation would be 10=x-3, then you just solve the equation which would be 7, hope that helped.
The new square has length: 10 + l, where l is the original length of the square, and it's area is (10 + l)^2;
So, we solve the equation: 3 x l^2 = (10 + l)^2;
Then, 3 x l^2 = 100 + 20 x l + l^2;
Finally, 2xl^2 - 20xl - 100 = 0; / ÷2;
l^2 - 10l - 50 = 0 (we use the quadratic equation formula);
The only positive solution is l = 5(1+ \sqrt{3} );
Answer:boo
Step-by-step explanation:I a ghost
Scientific notation, is a way of writing numbers that accommodates values that's too large or too small to be conveniently written or comprehended in standard decimal notation. ... Scientific notation is important to modern society because it provides to people working with these numbers.
