cot(<em>θ</em>) = cos(<em>θ</em>)/sin(<em>θ</em>)
So if both cot(<em>θ</em>) and cos(<em>θ</em>) are negative, that means sin(<em>θ</em>) must be positive.
Recall that
cot²(<em>θ</em>) + 1 = csc²(<em>θ</em>) = 1/sin²(<em>θ</em>)
so that
sin²(<em>θ</em>) = 1/(cot²(<em>θ</em>) + 1)
sin(<em>θ</em>) = 1 / √(cot²(<em>θ</em>) + 1)
Plug in cot(<em>θ</em>) = -2 and solve for sin(<em>θ</em>) :
sin(<em>θ</em>) = 1 / √((-2)² + 1)
sin(<em>θ</em>) = 1/√(5)
The answer is 53
——————————-
Answer:
#3
<u>What was the area left unpainted?</u>
Option D
#4
<u>How big is Ben's share?</u>
- 998.50 - 18.6² = 652.54 m²
Option A
#5
<u>The area of a circular pool whose radius is 2 m:</u>
- A = π² = 3.14*2² = 12.56 m²
Option A
Answer:
C
Step-by-step explanation:
Answer:
D
Step-by-step explanation:
To convert from polar to rectangular form
• x = rcosΘ , y = rsinΘ
• r = 
⇒ r² = x² + y²
Given
r = 8cosΘ
r = 8 × 
( multiply both sides by r )
r² = 8x, hence
x² + y² = 8x ⇒ D
