Answer:
The required equation is
.
Step-by-step explanation:
The equation of line cd is

Slope intercept form of a line is

Where, m is slope and b is y-intercept.
Slope of line cd is 3.
The product of slopes of two perpendicular lines is -1.



Therefore slope of perpendicular line is
.
Point slope form of a line is

Slope of perpendicular line is
and line passing through the point (3,1).



Therefore the required equation is
.
Factor out the common terms in the first two terms, then in the last two terms;
3x^2(b - 3x) - (b - 3x)
Factor out the common term b - 3x
<u>= (b - 3x)(3x^2 - 1)</u>
Answer:
132.73
Step-by-step explanation:
the equation for area of a circle is A=πr*2
if your diameter is 13 simply take half of that and plug into the equation
π(6.5)*2 which when put into a calculator comes out to 132.732289
It's difficult to make out what the force and displacement vectors are supposed to be, so I'll generalize.
Let <em>θ</em> be the angle between the force vector <em>F</em> and the displacement vector <em>r</em>. The work <em>W</em> done by <em>F</em> in the direction of <em>r</em> is
<em>W</em> = <em>F</em> • <em>r</em> cos(<em>θ</em>)
The cosine of the angle between the vectors can be obtained from the dot product identity,
<em>a</em> • <em>b</em> = ||<em>a</em>|| ||<em>b</em>|| cos(<em>θ</em>) ==> cos(<em>θ</em>) = (<em>a</em> • <em>b</em>) / (||<em>a</em>|| ||<em>b</em>||)
so that
<em>W</em> = (<em>F</em> • <em>r</em>)² / (||<em>F</em>|| ||<em>r</em>||)
For instance, if <em>F</em> = 3<em>i</em> + <em>j</em> + <em>k</em> and <em>r</em> = 7<em>i</em> - 7<em>j</em> - <em>k</em> (which is my closest guess to the given vectors' components), then the work done by <em>F</em> along <em>r</em> is
<em>W</em> = ((3<em>i</em> + <em>j</em> + <em>k</em>) • (7<em>i</em> - 7<em>j</em> - <em>k</em>))² / (√(3² + 1² + 1²) √(7² + (-7)² + (-1)²))
==> <em>W</em> ≈ 5.12 J
(assuming <em>F</em> and <em>r</em> are measured in Newtons (N) and meters (m), respectively).