Answer:
x^2+y^2 = 3^2
Step-by-step explanation:
We need to eliminate the parameter t
Given:
x = 3 cos t
y = 3 sin t
Squaring the above both equations
(x)^2=(3 cos t)^2
(y)^2 =(3 sin t)^2
x^2 = 3^2 cos^2t
y^2=3^2 sin^2t
Now adding both equations
x^2+y^2=3^2 cos^2t+3^2 sin^2t
Taking 3^2 common
x^2+y^2=3^2 (cos^2t+sin^2t)
We know that cos^2t+sin^2t = 1
so, putting the value
x^2+y^2=3^2(1)
x^2+y^2 = 3^2
Hence the parameter t is eliminated.
The answer to this question is D (2,-2)
Answer:
0
Step-by-step explanation:
180-180=0
counter clockwise
Answer:
It will take the first person 12 days and the second person x+12 or 20 days
Step-by-step explanation:
The equation for time to do a job is
1/A + 1/B = 1/C
where A is the time for person A to do the job alone
B is the time for person B to do the job alone
and C is the time for A and B to do the job together
Person A does it in x days and Person B does it in x+8 days and together they do it in 7.5 days
Substituting in
1/ (x) + 1/ (x+8) = 1/ 7.5
Multiply by (x)(x+8)(7.5) to clear the fractions
(x)(x+8)(7.5)(1/ (x) + 1/ (x+8)) = (1/ 7.5)(x)(x+8)(7.5)
Distribute
(x)(x+8)(7.5)(1/ (x)) +(x)(x+8)(7.5)( 1/ (x+8)) = (1/ 7.5)(x)(x+8)(7.5)
Cancel
(x+8)(7.5) + 7.5x = (x)(x+8)
Distribute
7.5x +60 +7.5x = x^2 +8x
Combine like terms
15x +60 = x^2 +8x
Subtract 15x from each side
15x-15x +60 = x^2 +8x-15x
60 = x^2 -7x
Subtract 60 from each side
60-60 = x^2 -7x - 60
0 = x^2 -7x - 60
Factor
0 = (x-12) *(x+5)
Using the zero product property
x-12=0 x+5=0
x=12 x=-5
Since the number of days cannot be zero
It will take the first person 12 days and the second person x+12 or 20 days
Candle A burns 72 minutes
Candle B burns 36 minutes
Candle C burns 12 minutes
Hope this helps!