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:
24
Step-by-step explanation:
6 / 1 / 4 =
6 x 4 =
24
B/5 > 30
we’re going to simplify by multiplying by 5 on both sides.
b > 150 should be the answer!
Answer:
m∠8 = 49°
Step-by-step explanation:
∠7 and ∠8 are same-side interior angles.
Remember, same-side interior angles are supplementary. This means that the sum of the angles is 180°.
Let's use the variable 'x' to represent the unknown measure of angle ∠8.
(cancels itself out)
Therefore, the measure of ∠8 is 49°.
Only once, any number higher will pass it
