Answer:
θ = 2π/3 or 5π/3
Step-by-step explanation:
2 cosθ + 1= 0
when + 1 goes to R H S Side than it becomes negative by transposition method
2 cos = -1
now by dividing by 2 both sides we get
cosθ = -
since cosθ is negative
Cosθ = - cos 60°
it means either cosθ lies in 2nd or third quadrant
θ = π - π/3
or
θ = 2π- π/3
so θ = 2π/3 or 5π/3
Answer:


Step-by-step explanation:
i is an imaginary unit, this means

Rewrite -5 as 
then

Rewrite -25 as 
then

1. Let x = #
2. "Five less than six times a number" can be written as: 6x - 5
3. "is at least" is the same as "greater than or equal to" and can be written as: >=
4. "nine subtracted from two times that number" can be written as: 2x - 9
5. the equation is: 6x - 5 >= 2x - 9
6. solve for x by grouping the x variable terms on one side and the constants on the other side:
6x - 5 >= 2x - 9
-2x +5 -2X +5
4x >= -4
7. divide each side by 4, and you get: x = -1
Area of the shaded region = Area <span>of a square - Area of a circle
</span>
Side of a square = 2r
Area of a square = (2r)² = 4r²
Area of a circle = πr²
Area of the shaded region = 4r² - πr² = r²(4-π)