AC = 30 mm (millimeters)
CF = 20 mm (millimeters)
EG = 0.1 m (meters)
The last question only had one “m” so I’m assuming it’s meters
Use both!
You want to minimize <em>P</em>, so differentiate <em>P</em> with respect to <em>x</em> and set the derivative equal to 0 and solve for any critical points.
<em>P</em> = 8/<em>x</em> + 2<em>x</em>
d<em>P</em>/d<em>x</em> = -8/<em>x</em>² + 2 = 0
8/<em>x</em>² = 2
<em>x</em>² = 8/2 = 4
<em>x</em> = ± √4 = ± 2
You can then use the second derivative to determine the concavity of <em>P</em>, and its sign at a given critical point decides whether it is a minimum or a maximum.
We have
d²<em>P</em>/d<em>x</em>² = 16/<em>x</em>³
When <em>x</em> = -2, the second derivative is negative, which means there's a relative maximum here.
When <em>x</em> = 2, the second derivative is positive, which means there's a relative minimum here.
So, <em>P</em> has a relative maximum value of 8/(-2) + 2(-2) = -8 when <em>x</em> = -2.
The correct answer is: Option (D) x = 72°
Explanation:
When two lines are crossed by another line, the angles in matching corners are called <em>corresponding angles</em>. When the two lines are <em>parallel</em>, the corresponding angles are <em>equal</em>.
Here in this case, the two lines are "AB" and "CD", and both are parallel and are crossed by the line; therefore, <em>the corresponding angles will be the same</em>.
Since the first corresponding angle is 72°, the second angle <em>x </em>will be 72° as well. The correct answer is: x = 72° Option (D).
I'm not sure if i am correct but i would say
[ 0,1 ]
You can re-write this quotient this way :
What's inside the square root must be greater than or equal to 0, because the domain of the square root function is defined on R+ (which is [0,+∞))
In other word we must find x so that :
at the end we get
28(x-1) ≥ 0
28x - 28 ≥ 0
28x ≥ 28
x ≥ 1
So the answer is B, x ≥ 1
