4x + y = 5
3x + y = 8
y = -3x + 8
4x +(-3x + 8) = 5
4x -3x + 8 = 5
x + 8 = 5
x = -3
y = -3(-3) + 8
y = -9 + 8
y = -1
These are two questions and two answers.
Question 1) Which of the following polar equations is equivalent to the parametric equations below?
<span>
x=t²
y=2t</span>
Answer: option <span>A.) r = 4cot(theta)csc(theta)
</span>
Explanation:
1) Polar coordinates ⇒ x = r cosθ and y = r sinθ
2) replace x and y in the parametric equations:
r cosθ = t²
r sinθ = 2t
3) work r sinθ = 2t
r sinθ/2 = t
(r sinθ / 2)² = t²
4) equal both expressions for t²
r cos θ = (r sin θ / 2 )²
5) simplify
r cos θ = r² (sin θ)² / 4
4 = r (sinθ)² / cos θ
r = 4 cosθ / (sinθ)²
r = 4 cot θ csc θ ↔ which is the option A.
Question 2) Which polar equation is equivalent to the parametric equations below?
<span>
x=sin(theta)cos(theta)+cos(theta)
y=sin^2(theta)+sin(theta)</span>
Answer: option B) r = sinθ + 1
Explanation:
1) Polar coordinates ⇒ x = r cosθ, and y = r sinθ
2) replace x and y in the parametric equations:
a) r cosθ = sin(θ)cos(θ)+cos(θ)
<span>
b) r sinθ =sin²(θ)+sin(θ)</span>
3) work both equations
a) r cosθ = sin(θ)cos(θ)+cos(θ) ⇒ r cosθ = cosθ [ sin θ + 1] ⇒ r = sinθ + 1
<span>
b) r sinθ =sin²(θ)+sin(θ) ⇒ r sinθ = sinθ [sinθ + 1] ⇒ r = sinθ + 1
</span><span>
</span><span>
</span>Therefore, the answer is r = sinθ + 1 which is the option B.
The annual income tax paid by the person is: $4,500.
<h3>Annual income tax</h3>
Using this formula
Annual income tax=[Salary÷(1-percentage deduction)]- Salary
Let plug in the formula
Annual income tax=[40,500÷(1-10%)]-40,500
Annual income tax=45,000-40,500
Annual income tax=4500
Therefore the annual income tax paid by the person is: $4,500.
Learn more about annual income tax here:brainly.com/question/26316390
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9 then 8. You add 4 to each number then subtract 1. 5+4=9 9-1=8
