Answer:
A-8
Step-by-step explanation:
Any other higher number plugged in makes the equation false
It would be -15 I think just calculate it to make sure xx
(a) If the particle's position (measured with some unit) at time <em>t</em> is given by <em>s(t)</em>, where

then the velocity at time <em>t</em>, <em>v(t)</em>, is given by the derivative of <em>s(t)</em>,

(b) The velocity after 3 seconds is

(c) The particle is at rest when its velocity is zero:

(d) The particle is moving in the positive direction when its position is increasing, or equivalently when its velocity is positive:

In interval notation, this happens for <em>t</em> in the interval (0, √11) or approximately (0, 3.317) s.
(e) The total distance traveled is given by the definite integral,

By definition of absolute value, we have

In part (d), we've shown that <em>v(t)</em> > 0 when -√11 < <em>t</em> < √11, so we split up the integral at <em>t</em> = √11 as

and by the fundamental theorem of calculus, since we know <em>v(t)</em> is the derivative of <em>s(t)</em>, this reduces to

This can be solver by creating a small equation with x being the number and solving for x. The equation would be 8 + 2( x + 3 ) = -6
Solve for x:
8 + 2( x + 3 ) = -6
Distribute the 2
8+ (2x+6)=-6
Subtract 8
2x+6= -14
Add 6
2x= 8
Divide by 2
x=4
So the number you are looking for is 4
I hope this helps!