Answer:

Step-by-step explanation:
A complex number is defined as z = a + bi. Since the complex number also represents right triangle whenever forms a vector at (a,b). Hence, a = rcosθ and b = rsinθ where r is radius (sometimes is written as <em>|z|).</em>
Substitute a = rcosθ and b = rsinθ in which the equation be z = rcosθ + irsinθ.
Factor r-term and we finally have z = r(cosθ + isinθ). How fortunately, the polar coordinate is defined as (r, θ) coordinate and therefore we can say that r = 4 and θ = -π/4. Substitute the values in the equation.
![\displaystyle \large{z=4[\cos (-\frac{\pi}{4}) + i\sin (-\frac{\pi}{4})]}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Clarge%7Bz%3D4%5B%5Ccos%20%28-%5Cfrac%7B%5Cpi%7D%7B4%7D%29%20%2B%20i%5Csin%20%28-%5Cfrac%7B%5Cpi%7D%7B4%7D%29%5D%7D)
Evaluate the values. Keep in mind that both cos(-π/4) is cos(-45°) which is √2/2 and sin(-π/4) is sin(-45°) which is -√2/2 as accorded to unit circle.

Hence, the complex number that has polar coordinate of (4,-45°) is 
Answer:
sin s = 36 / 42 = 18 / 21 = 6/ 7
sin R = 14 / 42 = 7 / 21 = 1 / 3
cos s = 14 / 42 = 1 / 3
cos R = 36 / 42 = 6 / 7
Answer:
The area in factored form is
.
The area in standard form is
.
Step-by-step explanation:
The area of a rectangle is length times width.
So the area here is (x+2)(x-5).
They are probably not looking for A=(x+2)(x-5) because it requires too little work.
They probably want A in standard form instead of factored form.
Let's use foil:
First x(x)=x^2
Outer: x(-5)=-5x
Inner: 2(x)=2x
Last: 2(-5)=-10
---------------------Adding together:
.
The area in factored form is
.
The area in standard form is
.
Area = length x width = (0.8 x 5280) x (1.1 x 5280) = 4224 x 5808 = 24532992 square feet.
43,560 square feet = 1 acre
24,532,992 square feet = 24,532,992/43,560 = 563.2 acre