All categories

3 years ago

What is the nth term of the arithmetic sequence? 7, 5, 3, 1, …

2 answers:

6 0

An=a1+d(n-1)
an=nth term
a1=first term
d=common difference

7 is first term=a1
the common difference is -2, they increase by -2 each time
an=7-2(n-1)
expand and distribute
an=7-2n+2
an=9-2n

C is answer

vampirchik [111]3 years ago

6 0

Hello,

a(1)=7=9-2*1
a(2)=5=9-2*2
a(3)=3=9-2*3
..
a(n)=?=9-2*n

Answer C

You might be interested in

See the picture below

mart [117]

Answer:

a) 301.59 cubic centimeters

b) 235.87 square centimeters

Step-by-step explanation:

Volume of ice cream cone is volume of hemisphere PLUS volume of cone.

Volume of Hemisphere = $\frac{\frac{4}{3}\pi r^3}{2}$

radius is given as 4, so,

Volume of Hemisphere = $\frac{\frac{4}{3}\pi r^3}{2}\\=\frac{\frac{4}{3}\pi (4)^3}{2}\\=134.04$

Now, Volume of Cone = $\frac{1}{3}\pi r^2 h$

Where radius is 4 and height is 10, so,

Volume of Cone = $\frac{1}{3}\pi r^2 h\\=\frac{1}{3}\pi (4)^2 (10)\\=167.55$

Volume of Ice Cream Cone = 134.04 + 167.55 = 301.59 cubic centimeters

Surface area of ice cream cone is surface area of hemisphere PLUS surface area of cone.

Surface Area of Hemisphere = $2\pi r^2\\=2\pi (4)^2\\=100.53$

Surface Area of Cone = $\pi r^2+\pi rl$

We dont need to use the first part, $\pi r^2$ since it is "inside". We need to find l, slant height, by using pythagorean theorem on a triangle we can make (bottom right).

4^2 + 10^ 2 = l^2

16 + 100 = l^2

116 = l^2

l = 10.77

Now to find the surface area of cone = $\pi rl\\=\pi (4)(10.77)\\=135.34$

Surface area of ice cream cone = 100.53 + 135.34 = 235.87 square centimeters

5 0

2 years ago

What is the exact value of sin -840

dsp73

First subtract 2 revolutions from the - 840 :- (- (840-720) = -120

This gives sin -120 which is in the 3rd quadrant of the unit circle

sin -120 = - sin 60 = - sqrt3/2

7 0

3 years ago

You're having dinner at a restaurant that serves 555 kinds of pasta (spaghetti, bow ties, fettuccine, ravioli, and macaroni) in

NARA [144]

Answer:

19/20

Step-by-step explanation:

I got help on khan acadamy!!!!!

7 0

3 years ago

Express 153,000 in scientific notation

andre [41]