The answer is 1690. First find
the amount of interest by a single investment by multiplying the investment
amount by the percent interest in decimal form. Then calculate the total by
adding up all the products of investment times interest. Matrices will allow to
multiply two things together and add the products up all at the same time. So
we need to find the investment matrix and interest matrix.
Investment matrix A (transposed) = (a1 a2 a3) = (13,000 12,000 4,000)
Interest Matrix B = (b1
b2 b3) = (0.05 0.06 0.08)
Amount of interest earned = a1b1 + a2b2 + a3b3
Amount of interest earned = (0.05) (13,000) + (0.06)
(12,000) + (0.08)(4,000)
Amount of interest earned = 1690
The total percentage of the equation is 1,597.72
ANSWER:
r = 
Explaination:
Convert the given curve into the the polar form.
x = rcosθ
y = rsinθ
in f(x,y) = (x²-y²) - √(x²+y²) = 0
put the values of x & y in given curve equation.
We get at,
g(r,θ) = (r²cos²θ - r²sin²θ) - √(r²cos²θ + r²sin²θ) = 0
g(r,θ) = r²(cos²θ - sin²θ) - √r² = 0
We know that,
cos²θ - sin²θ = cos2θ
g(r,θ) = r²(cos2θ) - r = 0
Solve for r
Finally we get:
r = 
Answer:
A foot is a unit of length equal to exactly 12 inches or 0.3048 meters