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 mistake is there is no parenthesis around 4x+12
The information about the rational numbers and integers shows that the correct option is C.
<h3>How to explain the information?</h3>
It should be noted that rational numbers are numbers where we can write as a fraction of two integers. Any rational number is in the form a/b where a,b are integers and b is nonzero.
Terminating decimals can be written as a rational number. Something like 3.1 is equivalent to 31/10.
Of the four answer choices, only choice C is correct.
Choice A has the value '3' as a rational number, but it doesn't have it in the set of integers as well. So that's why choice A is incorrect.
Choice B has -3.4 in the set of integers, which is not correct. Integers do not have any decimal portion. The same applies to choice D also. We can rule choices B and D out.
Therefore, the correct option is C.
Learn more about integers on:
brainly.com/question/17695139
#SPJ1
<span>20-9x=11
-9x=11-20
-9x= -9
x= -9/(-9)
x=1
4(2x+1)=8
2x+1=8/4
2x+1=2
2x=2-1
2x=1
x=1/2
x=0.5
5(2x+5)=-15
2x+5= -15/5
2x+5= -3
2x= -3-5
2x= -8
x= -8/2
x=-4
3(8x+1)=-21
8x+1= -21/3
8x+1= -7
8x= -7-1
8x =-8
x= -8/8
x= -1
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Step-by-step explanation:
width= w
length = l=w+5
Area = l * w
104 =(w+5) * w
w2 +5w -104 =0
(w+13)(w-8)=0
w=13 and w=8
so width =8
length=13
