Answer:
no ( 9,22) is not a solution to the system of inequalities but 22os to long to fit in the space
Step-by-step explanation:
i hope this is helpful.
7x - 9 < 12
7x < 12 + 9
7x < 21
x < 21/7
x < 3
1/4x + 8 > 11
1/4x > 11 - 8
1/4x > 3
x > 3 * 4
x > 12
solution : x < 3 or x > 12
<span>since sin and cos = each other at pi/4; take your integrals from 0 to pi/4
</span><span>[S] cos(t) dt - [S] sin(t) dt ;[0,pi/4]
</span>
<span>to revolve it around the x axis;
we do a sum of areas
[S] 2pi [f(x)]^2 dx
</span>
<span>take the cos first and subtract out the sin next; like cutting a hole out of a donuts.
</span><span>pi [S] cos(x)^2 dx - [S] sin(x)^2 dx ; [0,pi/4]
</span>
<span>cos(2t) = 2cos^2 - 1
cos^2 = (1+cos(2t))/2
</span>
<span>1/sqrt(2) - (-1/sqrt(2) +1)
1/sqrt(2) + 1/sqrt(2) -1
(2sqrt(2) - sqrt(2))/sqrt(2) = sqrt(2)/sqrt(2) = 1</span>
