(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)):
Y-axis, because what i’ve been taught with coordinates, is you crawl before you walk which means is first it’s x-axis then y-axis. so (0,4) would be on the y-axis. :)
12 ft * 10 ft = 120 sq ft
½ * 6 ft * 7 ft = 21 sq ft
120 sq ft - 21 sq ft = 99 sq ft (it is area of the composite shape)
When we substitute a specific valuefor each variable, and then perform the operations, it's called evaluating theexpression. Let's evaluate theexpression 3y + 2y when 5 = y. Click on the steps to see how it's done. Perform the operations, to find the value of the expression.
