From the equation, it looks like we can set up a triangle like this. One side is x and the other is x + 20 because the northbound car traveled 20 miles farther. The hypotenuse is 100 because they were 100 miles apart.
Next, we can use the Pythagorean Theorem to solve for x:
a² + b² = c²
x² + (x + 20)² = 100²
This simplifies to:
x² + x² + 40x + 400 = 10000
2x² + 40x = 9600
2x² + 40x - 9600 = 0
After that, we can divided each side by 2:
x² + 20x - 4800 = 0
Next, we have to factor:
(x - 60)(x + 80) = 0
x = 60, -80
Since we know that distance can't be negative, 60 is the valid answer in this case.
x = 60
x + 20 = 80
Using this information, we know that the westbound car traveled 60 miles and the northbound car traveled 80 miles.
The area of the surface is 144.708
The equation of the given surface is,
z=g(x,y)=xy
Solving the partial derivatives,
∂g∂x=y,∂g∂y=x
Substituting to the formula
S=∬√1+( ∂g∂x)2+(∂g∂y)2dA
Thus,
S=∬√1+(y)2+(x)2dAS=∬√1+x2+y2dA
The region in the XY-plane is defined by the intervals 0≤θ≤2π,0≤r≤4
Converting the integral into polar coordinates,
S=∫2π0∫40√1+r2rdrdθ
Integrating with respect to r
S=∫2π0[13(1+r2)32]40dθ
S=∫2π0(17√173−13)dθ
Integrating with respect to θ
S=(17√173−13)[θ]2π0
S≈144.708
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Answer:
yo have to think very hard about it
A line is a straight one-dimensional figure having no thickness and extending infinitely in both directions.