Answer:
Step-by-step explanation:
Remember, the formulas for the lateral surface area of a pyramid is 12pl and the total surface area is 12pl+B .
Since the base of a cone is a circle, we substitute 2πr for p and πr2 for B where r is the radius of the base of the cylinder.
So, the formula for the lateral surface area of a right cone is L.S.A=πrl , where l is the slant height of the cone.
Find the lateral surface area of a right cone if the radius is 4 cm and the slant height is 5 cm.
L.S.A=π(4)(5)=20π≈62.82 cm2
Answer:
b
Step-by-step explanation:
Because y is squared, or, actually, because (y + 6) is squared, we know immediately that the graph is horizontal. Because both (y + 6)^2 and (x - 7) are positive, we know that the graph opens to the right. (b) is correct.
Figure B i imagine is correct
The game has to be 12 because he plays 12 games and each day he plays for a long time
Answer:
10 friends
Step-by-step explanation:
we know that
The formula of the sum is equal to
![sum=\frac{n}{2}[2a1+(n-1)d]](https://tex.z-dn.net/?f=sum%3D%5Cfrac%7Bn%7D%7B2%7D%5B2a1%2B%28n-1%29d%5D)
where
a1 is the first term
n is the number of terms (number of friends)
d is the common difference in the arithmetic sequence
In this problem we have
----> the common difference
substitute in the formula and solve for n
![275=\frac{n}{2}[2(5)+(n-1)(5)]](https://tex.z-dn.net/?f=275%3D%5Cfrac%7Bn%7D%7B2%7D%5B2%285%29%2B%28n-1%29%285%29%5D)
![550=n[10+5n-5]\\ \\550=10n+5n^{2} -5n\\ \\5n^{2}+5n-550=0](https://tex.z-dn.net/?f=550%3Dn%5B10%2B5n-5%5D%5C%5C%20%5C%5C550%3D10n%2B5n%5E%7B2%7D%20-5n%5C%5C%20%5C%5C5n%5E%7B2%7D%2B5n-550%3D0)
Solve the quadratic equation by graphing
The solution is n=10
see the attached figure
therefore
She had 10 friends who got stickers
