(a) If <em>f(x)</em> is to be a proper density function, then its integral over the given support must evaulate to 1:
For the integral, substitute <em>u</em> = <em>x</em> ² and d<em>u</em> = 2<em>x</em> d<em>x</em>. Then as <em>x</em> → 0, <em>u</em> → 0; as <em>x</em> → ∞, <em>u</em> → ∞:
which reduces to
<em>c</em> / 2 (0 + 1) = 1 → <em>c</em> = 2
(b) Find the probability P(1 < <em>X </em>< 3) by integrating the density function over [1, 3] (I'll omit the steps because it's the same process as in (a)):
We have the following equation:
h (t) = - 16t ^ 2 + 161t + 128
We substitute the value of h (t) = 170:
170 = -16t ^ 2 + 161t + 128
We rewrite the equation:
-16t ^ 2 + 161t + 128 - 170 = 0
-16t ^ 2 + 161t - 42 = 0
We look for the roots of the equation:
t1 = (161/32) + root (23233) / 32
t2 = (161/32) - root (23233) / 32
Answer:
The object is 170 feet off the ground at the following times:
t1 = (161/32) + root (23233) / 32
t2 = (161/32) - root (23233) / 32
Answer:
It was helpful to construct points D and A to be the same distance from C because it gives you an equal arc on both sides, which will intersect twice, forming a colinear line that is perpendicular to line AB.
Step-by-step explanation:
8%=0.08
42÷0.08=525
So your answer is 525
