Answer:
Eq: (x+a/2)²+(y+1)²=(a²-8)/4
Center: O(-a/2, -1)
Radius: r=0.5×sqrt(a²-8)
Mandatory: a>2×sqrt(2)
Step-by-step explanation:
The circle with center in O(xo,yo) and radius r has the equation:
(x-xo)²+(y-yo)²=r²
We have:
x²+y²+ax+2y+3=0
But: x²+ax=x²+2(a/2)x+a²/4-a²/4= (x+a/2)²-a²/4
And
y²+2y+3=y²+2y+1+2=(y+1)²+2
Replacing, we get:
(x+a/2)²-a²/4+(y+1)²+2=0
(x+a/2)²+(y+1)²=a²/4-2=(a²-8)/4
By visual inspection we note that:
- center of circle: O(-a/2, -1)
- radius: r=sqrt((a²-8)/4)=0.5×sqrt(a²-8). This means a²>8 or a>2×sqrt(2)
Answer:
Convergent; 81
Step-by-step explanation:
r = term2/term1 = 8/9
8/9 < 1 so convergent
Sum = 9/(1 - 8/9)
= 9/(1/9) = 81
Well,
We can see that there are 8 10's and 3 1's. So we can write 8 10's followed by 3 1's and join them with addition symbols.
83 = 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 1 + 1 + 1
9514 1404 393
Answer:
x ≠ 3
Step-by-step explanation:
In any case, the domain is restricted to values of the variable for which the function is defined. The value 1/0 is not defined, so the variable cannot allow the denominator to be zero. The denominator x-3 will be zero for x=3, so that value of the variable cannot be in the domain.
The domain is all real numbers except x=3.
_____
<em>Additional comments</em>
It is useful to become familiar with the domains of different functions. As we saw above, the reciprocal of 0 is undefined. The square root of a negative number is undefined. The log of a non-positive number is undefined. Trig functions are defined everywhere, but their inverse functions are not. Polynomial functions are defined everywhere, but ratios of polynomials have the same restriction on denominators that we see above.
Answer:
y = 3
Step-by-step explanation:
substitute the x in 2x - y = 7 by x = 3y - 4 and then solve
2(3y - 4) - y = 7
<em>Distribute the 2 into the parenthesis</em>
6y - 8 -y = 7
<em>combine like terms</em>
5y - 8 = 7
<em>add 8 on both sides</em>
5y = 15
<em>divide by 5 on both sides to isolate the y-value</em>
y = 3
