Answer:
two real, unequal roots
Step-by-step explanation:
This is a quadratic equation. The quadratic formula can be used to determine how many and what kind of roots may exist:
Find the discriminant, which is defined as b^2 - 4ac, if ax^2 + bx + c = 0. In this case, a = 1, b = -2 and c = -8, so that the discriminant value is
(-2)^2 - 4(1)(-8), or 4 + 32 = 36.
Because the discriminant is real and positive, we know for certain that we have two real, unequal roots
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: 5/12
Step-by-step explanation: