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>
i think answer is 8in2
please talk me my answer is correct or not
for the first one set 3y+y=180 and y+x=180
the second one set w+y=180, 42+x=180, y+20=180, and 87+v
Answer:
a=b+cd
c=b/c/a or c^2=b/a
Btw ^2 means squared or to the second power.
this might no be the answer you are looking for though
Steps to solve:
10.2x + 9.4y when x = 2 and y = 3
= 10.2(2) + 9.4(3)
= 20.4 + 28.2
= 48.6
______
Best Regards,
Wolfyy :)
